21368409976 has 16 divisors (see below), whose sum is σ = 40069731240. Its totient is φ = 10683148320.

The previous prime is 21368409929. The next prime is 21368409977. The reversal of 21368409976 is 67990486312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21368409977) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42571 + ... + 211066.

Almost surely, 2^21368409976 is an apocalyptic number.

It is an amenable number.

21368409976 is a deficient number, since it is larger than the sum of its proper divisors (18701321264).

21368409976 is a wasteful number, since it uses less digits than its factorization.

21368409976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264174 (or 264170 counting only the distinct ones).

The product of its (nonzero) digits is 3919104, while the sum is 55.

The spelling of 21368409976 in words is "twenty-one billion, three hundred sixty-eight million, four hundred nine thousand, nine hundred seventy-six".