165966400 has 84 divisors (see below), whose sum is σ = 417259008. Its totient is φ = 64944640.

The previous prime is 165966397. The next prime is 165966403. The reversal of 165966400 is 4669561.

It is an interprime number because it is at equal distance from previous prime (165966397) and next prime (165966403).

It is a self number, because there is not a number n which added to its sum of digits gives 165966400.

It is not an unprimeable number, because it can be changed into a prime (165966403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 74097 + ... + 76303.

Almost surely, 2^165966400 is an apocalyptic number.

165966400 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 165966400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (208629504).

165966400 is an abundant number, since it is smaller than the sum of its proper divisors (251292608).

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

165966400 is a wasteful number, since it uses less digits than its factorization.

165966400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2276 (or 2261 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 165966400 is about 12882.7947278531. The cubic root of 165966400 is about 549.5493829748.

The spelling of 165966400 in words is "one hundred sixty-five million, nine hundred sixty-six thousand, four hundred".