165656400 has 480 divisors, whose sum is σ = 687122688. Its totient is φ = 33177600.

The previous prime is 165656399. The next prime is 165656423. The reversal of 165656400 is 4656561.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4040380 + ... + 4040420.

Almost surely, 2^165656400 is an apocalyptic number.

165656400 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 165656400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343561344).

165656400 is an abundant number, since it is smaller than the sum of its proper divisors (521466288).

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

165656400 is a wasteful number, since it uses less digits than its factorization.

165656400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 165656400 is about 12870.7575534620. The cubic root of 165656400 is about 549.2070114908.

The spelling of 165656400 in words is "one hundred sixty-five million, six hundred fifty-six thousand, four hundred".