21387838424 has 96 divisors (see below), whose sum is σ = 42389168400. Its totient is φ = 10111933440.

The previous prime is 21387838421. The next prime is 21387838441. The reversal of 21387838424 is 42483878312.

It is a super-2 number, since 2×21387838424² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21387838421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76113164 + ... + 76113444.

Almost surely, 2^21387838424 is an apocalyptic number.

It is an amenable number.

21387838424 is a deficient number, since it is larger than the sum of its proper divisors (21001329976).

21387838424 is a wasteful number, since it uses less digits than its factorization.

21387838424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513 (or 462 counting only the distinct ones).

The product of its digits is 2064384, while the sum is 50.

The spelling of 21387838424 in words is "twenty-one billion, three hundred eighty-seven million, eight hundred thirty-eight thousand, four hundred twenty-four".