21951275904 has 48 divisors (see below), whose sum is σ = 63167086320. Its totient is φ = 7317091584.

The previous prime is 21951275897. The next prime is 21951275917. The reversal of 21951275904 is 40957215912.

21951275904 is a `hidden beast` number, since 2 + 1 + 9 + 51 + 2 + 7 + 590 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21951275904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9526312 + ... + 9528615.

It is an arithmetic number, because the mean of its divisors is an integer number (1315980965).

Almost surely, 2^21951275904 is an apocalyptic number.

21951275904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21951275904 is an abundant number, since it is smaller than the sum of its proper divisors (41215810416).

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

21951275904 is a wasteful number, since it uses less digits than its factorization.

21951275904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19054947 (or 19054932 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 45.

The spelling of 21951275904 in words is "twenty-one billion, nine hundred fifty-one million, two hundred seventy-five thousand, nine hundred four".