Search a number
645120 = 2113257
BaseRepresentation
bin10011101100000000000
31012202221100
42131200000
5131120440
621454400
75324550
oct2354000
91182840
10645120
11400763
12271400
13197838
1412b160
15cb230
hex9d800

645120 has 144 divisors (see below), whose sum is σ = 2555280. Its totient is φ = 147456.

The previous prime is 645097. The next prime is 645131. The reversal of 645120 is 21546.

It is a happy number.

It is a Jordan-Polya number, since it can be written as 8! ⋅ (2!)4.

It is a double factorial (645120 = 14 !! = 2 ⋅ 4 ⋅ 6 ⋅ 8 ⋅ 10 ⋅ 12 ⋅ 14 ).

645120 is a `hidden beast` number, since 645 + 1 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 645093 and 645102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 92157 + ... + 92163.

It is an arithmetic number, because the mean of its divisors is an integer number (17745).

2645120 is an apocalyptic number.

645120 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1277640).

645120 is an abundant number, since it is smaller than the sum of its proper divisors (1910160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645120 is a wasteful number, since it uses less digits than its factorization.

645120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 645120 is about 803.1936254727. The cubic root of 645120 is about 86.4065838604.

Adding to 645120 its reverse (21546), we get a palindrome (666666).

It can be divided in two parts, 64 and 5120, that added together give a square (5184 = 722).

The spelling of 645120 in words is "six hundred forty-five thousand, one hundred twenty".