165566400 has 168 divisors, whose sum is σ = 575431920. Its totient is φ = 41533440.

The previous prime is 165566393. The next prime is 165566407. The reversal of 165566400 is 4665561.

It is an interprime number because it is at equal distance from previous prime (165566393) and next prime (165566407).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165566407) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 80586 + ... + 82614.

It is an arithmetic number, because the mean of its divisors is an integer number (3425190).

Almost surely, 2^165566400 is an apocalyptic number.

165566400 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 165566400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (287715960).

165566400 is an abundant number, since it is smaller than the sum of its proper divisors (409865520).

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

165566400 is a wasteful number, since it uses less digits than its factorization.

165566400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2071 (or 2056 counting only the distinct ones).

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

The square root of 165566400 is about 12867.2607807567. The cubic root of 165566400 is about 549.1075333236.

The spelling of 165566400 in words is "one hundred sixty-five million, five hundred sixty-six thousand, four hundred".