215942621868 has 96 divisors (see below), whose sum is σ = 579659888640. Its totient is φ = 69448104000.

The previous prime is 215942621857. The next prime is 215942621911. The reversal of 215942621868 is 868126249512.

215942621868 is a `hidden beast` number, since 2 + 1 + 5 + 9 + 4 + 2 + 621 + 8 + 6 + 8 = 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 31 ways as a sum of consecutive naturals, for example, 1010758 + ... + 1205618.

It is an arithmetic number, because the mean of its divisors is an integer number (6038123840).

Almost surely, 2^215942621868 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 215942621868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (289829944320).

215942621868 is an abundant number, since it is smaller than the sum of its proper divisors (363717266772).

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

215942621868 is a wasteful number, since it uses less digits than its factorization.

215942621868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195236 (or 195228 counting only the distinct ones).

The product of its digits is 3317760, while the sum is 54.

It can be divided in two parts, 21594 and 2621868, that added together give a palindrome (2643462).

The spelling of 215942621868 in words is "two hundred fifteen billion, nine hundred forty-two million, six hundred twenty-one thousand, eight hundred sixty-eight".