28056137220 has 72 divisors (see below), whose sum is σ = 85190728896. Its totient is φ = 7473978432.

The previous prime is 28056137209. The next prime is 28056137281. The reversal of 28056137220 is 2273165082.

28056137220 is a `hidden beast` number, since 2 + 8 + 0 + 561 + 3 + 72 + 20 = 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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 97659 + ... + 256221.

It is an arithmetic number, because the mean of its divisors is an integer number (1183204568).

Almost surely, 2^28056137220 is an apocalyptic number.

28056137220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28056137220 is an abundant number, since it is smaller than the sum of its proper divisors (57134591676).

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

28056137220 is a wasteful number, since it uses less digits than its factorization.

28056137220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159561 (or 159556 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The spelling of 28056137220 in words is "twenty-eight billion, fifty-six million, one hundred thirty-seven thousand, two hundred twenty".