21056545156 has 12 divisors (see below), whose sum is σ = 38119607820. Its totient is φ = 10165228640.

The previous prime is 21056545109. The next prime is 21056545157. The reversal of 21056545156 is 65154565012.

It can be written as a sum of positive squares in 2 ways, for example, as 4617202500 + 16439342656 = 67950^2 + 128216^2 .

It is not an unprimeable number, because it can be changed into a prime (21056545157) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90760855 + ... + 90761086.

It is an arithmetic number, because the mean of its divisors is an integer number (3176633985).

Almost surely, 2^21056545156 is an apocalyptic number.

It is an amenable number.

21056545156 is a deficient number, since it is larger than the sum of its proper divisors (17063062664).

21056545156 is a wasteful number, since it uses less digits than its factorization.

21056545156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181521974 (or 181521972 counting only the distinct ones).

The product of its (nonzero) digits is 180000, while the sum is 40.

The spelling of 21056545156 in words is "twenty-one billion, fifty-six million, five hundred forty-five thousand, one hundred fifty-six".