216870572556 has 144 divisors (see below), whose sum is σ = 620462868480. Its totient is φ = 65689081920.

The previous prime is 216870572537. The next prime is 216870572587. The reversal of 216870572556 is 655275078612.

216870572556 is a `hidden beast` number, since 2 + 1 + 6 + 87 + 0 + 5 + 7 + 2 + 556 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 44465590 + ... + 44470466.

It is an arithmetic number, because the mean of its divisors is an integer number (4308769920).

Almost surely, 2^216870572556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216870572556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (310231434240).

216870572556 is an abundant number, since it is smaller than the sum of its proper divisors (403592295924).

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

216870572556 is a wasteful number, since it uses less digits than its factorization.

216870572556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9066 (or 9052 counting only the distinct ones).

The product of its (nonzero) digits is 7056000, while the sum is 54.

The spelling of 216870572556 in words is "two hundred sixteen billion, eight hundred seventy million, five hundred seventy-two thousand, five hundred fifty-six".