165904400 has 60 divisors (see below), whose sum is σ = 400471764. Its totient is φ = 66048000.

The previous prime is 165904393. The next prime is 165904421. The reversal of 165904400 is 4409561.

It can be written as a sum of positive squares in 6 ways, for example, as 2166784 + 163737616 = 1472^2 + 12796^2 .

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, 95540 + ... + 97260.

Almost surely, 2^165904400 is an apocalyptic number.

165904400 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 165904400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (200235882).

165904400 is an abundant number, since it is smaller than the sum of its proper divisors (234567364).

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

165904400 is a wasteful number, since it uses less digits than its factorization.

165904400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1980 (or 1969 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 165904400 is about 12880.3881929079. The cubic root of 165904400 is about 549.4809428058.

The spelling of 165904400 in words is "one hundred sixty-five million, nine hundred four thousand, four hundred".