21504642344 has 16 divisors (see below), whose sum is σ = 40384117620. Its totient is φ = 10735544320.

The previous prime is 21504642331. The next prime is 21504642347. The reversal of 21504642344 is 44324640512.

It can be written as a sum of positive squares in 2 ways, for example, as 14680230244 + 6824412100 = 121162^2 + 82610^2 .

It is not an unprimeable number, because it can be changed into a prime (21504642347) 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, 2091659 + ... + 2101914.

Almost surely, 2^21504642344 is an apocalyptic number.

It is an amenable number.

21504642344 is a deficient number, since it is larger than the sum of its proper divisors (18879475276).

21504642344 is a wasteful number, since it uses less digits than its factorization.

21504642344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4194220 (or 4194216 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 35.

The spelling of 21504642344 in words is "twenty-one billion, five hundred four million, six hundred forty-two thousand, three hundred forty-four".