21620334438 has 24 divisors (see below), whose sum is σ = 46846770048. Its totient is φ = 7206360912.

The previous prime is 21620334419. The next prime is 21620334457. The reversal of 21620334438 is 83443302612.

21620334438 is a `hidden beast` number, since 2 + 1 + 6 + 203 + 3 + 443 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (21620334419) and next prime (21620334457).

It is a super-2 number, since 2×21620334438² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 556731 + ... + 594297.

It is an arithmetic number, because the mean of its divisors is an integer number (1951948752).

Almost surely, 2^21620334438 is an apocalyptic number.

21620334438 is an abundant number, since it is smaller than the sum of its proper divisors (25226435610).

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

21620334438 is a wasteful number, since it uses less digits than its factorization.

21620334438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69548 (or 69545 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The spelling of 21620334438 in words is "twenty-one billion, six hundred twenty million, three hundred thirty-four thousand, four hundred thirty-eight".