165664400 has 120 divisors (see below), whose sum is σ = 453345984. Its totient is φ = 57587200.

The previous prime is 165664391. The next prime is 165664409. The reversal of 165664400 is 4466561.

It is an interprime number because it is at equal distance from previous prime (165664391) and next prime (165664409).

It is not an unprimeable number, because it can be changed into a prime (165664409) 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, 100382 + ... + 102018.

Almost surely, 2^165664400 is an apocalyptic number.

165664400 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 165664400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (226672992).

165664400 is an abundant number, since it is smaller than the sum of its proper divisors (287681584).

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

165664400 is a wasteful number, since it uses less digits than its factorization.

165664400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1689 (or 1678 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 165664400 is about 12871.0683317276. The cubic root of 165664400 is about 549.2158522507.

It can be divided in two parts, 16 and 5664400, that multiplied together give a square (90630400 = 9520²).

The spelling of 165664400 in words is "one hundred sixty-five million, six hundred sixty-four thousand, four hundred".