216509599920 has 80 divisors (see below), whose sum is σ = 671284035072. Its totient is φ = 57726923520.

The previous prime is 216509599897. The next prime is 216509599937. The reversal of 216509599920 is 29995905612.

It is a tau number, because it is divible by the number of its divisors (80).

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 15 ways as a sum of consecutive naturals, for example, 1556425 + ... + 1689815.

Almost surely, 2^216509599920 is an apocalyptic number.

216509599920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216509599920 is an abundant number, since it is smaller than the sum of its proper divisors (454774435152).

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

216509599920 is a wasteful number, since it uses less digits than its factorization.

216509599920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140170 (or 140164 counting only the distinct ones).

The product of its (nonzero) digits is 3936600, while the sum is 57.

The spelling of 216509599920 in words is "two hundred sixteen billion, five hundred nine million, five hundred ninety-nine thousand, nine hundred twenty".