21156463506 has 16 divisors (see below), whose sum is σ = 42708376224. Its totient is φ = 6986246304.

The previous prime is 21156463481. The next prime is 21156463553. The reversal of 21156463506 is 60536465112.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16476355 + ... + 16477638.

It is an arithmetic number, because the mean of its divisors is an integer number (2669273514).

Almost surely, 2^21156463506 is an apocalyptic number.

21156463506 is an abundant number, since it is smaller than the sum of its proper divisors (21551912718).

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

21156463506 is a wasteful number, since it uses less digits than its factorization.

21156463506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32954105.

The product of its (nonzero) digits is 129600, while the sum is 39.

The spelling of 21156463506 in words is "twenty-one billion, one hundred fifty-six million, four hundred sixty-three thousand, five hundred six".