21655353504 has 96 divisors (see below), whose sum is σ = 57148217280. Its totient is φ = 7180111872.

The previous prime is 21655353479. The next prime is 21655353523. The reversal of 21655353504 is 40535355612.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22164664 + ... + 22165640.

It is an arithmetic number, because the mean of its divisors is an integer number (595293930).

Almost surely, 2^21655353504 is an apocalyptic number.

21655353504 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21655353504 is an abundant number, since it is smaller than the sum of its proper divisors (35492863776).

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

21655353504 is a wasteful number, since it uses less digits than its factorization.

21655353504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1982 (or 1974 counting only the distinct ones).

The product of its (nonzero) digits is 270000, while the sum is 39.

The spelling of 21655353504 in words is "twenty-one billion, six hundred fifty-five million, three hundred fifty-three thousand, five hundred four".