216571550556 has 24 divisors (see below), whose sum is σ = 527304645504. Its totient is φ = 69051798640.

The previous prime is 216571550549. The next prime is 216571550599. The reversal of 216571550556 is 655055175612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 392339490 + ... + 392340041.

It is an arithmetic number, because the mean of its divisors is an integer number (21971026896).

Almost surely, 2^216571550556 is an apocalyptic number.

It is an amenable number.

216571550556 is an abundant number, since it is smaller than the sum of its proper divisors (310733094948).

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

216571550556 is a wasteful number, since it uses less digits than its factorization.

216571550556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 784679561 (or 784679559 counting only the distinct ones).

The product of its (nonzero) digits is 1575000, while the sum is 48.

The spelling of 216571550556 in words is "two hundred sixteen billion, five hundred seventy-one million, five hundred fifty thousand, five hundred fifty-six".