216509673636 has 27 divisors (see below), whose sum is σ = 547295398923. Its totient is φ = 72168960600.

The previous prime is 216509673617. The next prime is 216509673649. The reversal of 216509673636 is 636376905612.

The square root of 216509673636 is 465306.

It is a perfect power (a square), and thus also a powerful number.

216509673636 is a `hidden beast` number, since 2 + 1 + 6 + 509 + 6 + 73 + 63 + 6 = 666.

216509673636 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2753061 + ... + 2830611.

Almost surely, 2^216509673636 is an apocalyptic number.

216509673636 is the 465306-th square number.

It is an amenable number.

216509673636 is an abundant number, since it is smaller than the sum of its proper divisors (330785725287).

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

216509673636 is an frugal number, since it uses more digits than its factorization.

216509673636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155112 (or 77556 counting only the distinct ones).

The product of its (nonzero) digits is 7348320, while the sum is 54.

The spelling of 216509673636 in words is "two hundred sixteen billion, five hundred nine million, six hundred seventy-three thousand, six hundred thirty-six".