21218792238 has 80 divisors (see below), whose sum is σ = 55663511904. Its totient is φ = 5914632960.

The previous prime is 21218792213. The next prime is 21218792249. The reversal of 21218792238 is 83229781212.

It is a junction number, because it is equal to n+sod(n) for n = 21218792193 and 21218792202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 181695 + ... + 274682.

Almost surely, 2^21218792238 is an apocalyptic number.

21218792238 is an abundant number, since it is smaller than the sum of its proper divisors (34444719666).

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

21218792238 is a wasteful number, since it uses less digits than its factorization.

21218792238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456439 (or 456430 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The spelling of 21218792238 in words is "twenty-one billion, two hundred eighteen million, seven hundred ninety-two thousand, two hundred thirty-eight".