21957481828 has 12 divisors (see below), whose sum is σ = 38472062832. Its totient is φ = 10965463880.

The previous prime is 21957481813. The next prime is 21957481849. The reversal of 21957481828 is 82818475912.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3315538 + ... + 3322153.

It is an arithmetic number, because the mean of its divisors is an integer number (3206005236).

Almost surely, 2^21957481828 is an apocalyptic number.

It is an amenable number.

21957481828 is a deficient number, since it is larger than the sum of its proper divisors (16514581004).

21957481828 is a wasteful number, since it uses less digits than its factorization.

21957481828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6638522 (or 6638520 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 55.

The spelling of 21957481828 in words is "twenty-one billion, nine hundred fifty-seven million, four hundred eighty-one thousand, eight hundred twenty-eight".