165216400 has 60 divisors (see below), whose sum is σ = 417842800. Its totient is φ = 62605440.

The previous prime is 165216349. The next prime is 165216437. The reversal of 165216400 is 4612561.

It is a Harshad number since it is a multiple of its sum of digits (25).

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, 3270 + ... + 18469.

Almost surely, 2^165216400 is an apocalyptic number.

165216400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165216400 is an abundant number, since it is smaller than the sum of its proper divisors (252626400).

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

165216400 is a wasteful number, since it uses less digits than its factorization.

165216400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21776 (or 21765 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 165216400 is about 12853.6531772100. The cubic root of 165216400 is about 548.7203307243.

Adding to 165216400 its reverse (4612561), we get a palindrome (169828961).

The spelling of 165216400 in words is "one hundred sixty-five million, two hundred sixteen thousand, four hundred".