1645200 has 90 divisors (see below), whose sum is σ = 5721794. Its totient is φ = 437760.

The previous prime is 1645187. The next prime is 1645211. The reversal of 1645200 is 25461.

It is a happy number.

1645200 is a `hidden beast` number, since 1 + 645 + 20 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 318096 + 1327104 = 564^2 + 1152^2 .

It is a tau number, because it is divible by the number of its divisors (90).

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

It is a plaindrome in base 13.

It is a zygodrome in base 15.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3372 + ... + 3828.

2^1645200 is an apocalyptic number.

1645200 is a gapful number since it is divisible by the number (10) 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 1645200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2860897).

1645200 is an abundant number, since it is smaller than the sum of its proper divisors (4076594).

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

1645200 is a wasteful number, since it uses less digits than its factorization.

1645200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481 (or 467 counting only the distinct ones).

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

The square root of 1645200 is about 1282.6534995859. The cubic root of 1645200 is about 118.0518779836.

The spelling of 1645200 in words is "one million, six hundred forty-five thousand, two hundred".