21591463104 has 84 divisors (see below), whose sum is σ = 63204876384. Its totient is φ = 7044014592.

The previous prime is 21591463087. The next prime is 21591463123. The reversal of 21591463104 is 40136419512.

It is a happy number.

21591463104 is a `hidden beast` number, since 2 + 1 + 5 + 9 + 14 + 631 + 0 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 371707 + ... + 425850.

Almost surely, 2^21591463104 is an apocalyptic number.

21591463104 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21591463104 is an abundant number, since it is smaller than the sum of its proper divisors (41613413280).

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

21591463104 is a wasteful number, since it uses less digits than its factorization.

21591463104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797622 (or 797609 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 21591463104 in words is "twenty-one billion, five hundred ninety-one million, four hundred sixty-three thousand, one hundred four".