Search a number
-
+
644485 = 5157821
BaseRepresentation
bin10011101010110000101
31012202001211
42131112011
5131110420
621451421
75322652
oct2352605
91182054
10644485
11400236
12270b71
1319746a
1412ac29
15cae5a
hex9d585

644485 has 8 divisors (see below), whose sum is σ = 779256. Its totient is φ = 511680.

The previous prime is 644447. The next prime is 644489. The reversal of 644485 is 584446.

644485 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 6084 + 638401 = 78^2 + 799^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2k-644485 is a prime.

It is a magnanimous number.

It is a d-powerful number, because it can be written as 67 + 46 + 48 + 49 + 85 + 5 .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644489) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 375 + ... + 1195.

It is an arithmetic number, because the mean of its divisors is an integer number (97407).

2644485 is an apocalyptic number.

It is an amenable number.

644485 is a deficient number, since it is larger than the sum of its proper divisors (134771).

644485 is a wasteful number, since it uses less digits than its factorization.

644485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 983.

The product of its digits is 15360, while the sum is 31.

The square root of 644485 is about 802.7982311889. The cubic root of 644485 is about 86.3782241790.

The spelling of 644485 in words is "six hundred forty-four thousand, four hundred eighty-five".

Divisors: 1 5 157 785 821 4105 128897 644485