21456155640528 has 240 divisors, whose sum is σ = 73329077352960. Its totient is φ = 5716788793344.

The previous prime is 21456155640509. The next prime is 21456155640533. The reversal of 21456155640528 is 82504655165412.

21456155640528 is a `hidden beast` number, since 2 + 1 + 4 + 5 + 6 + 1 + 55 + 64 + 0 + 528 = 666.

It is a super-2 number, since 2×21456155640528² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3875800 + ... + 7611447.

It is an arithmetic number, because the mean of its divisors is an integer number (305537822304).

Almost surely, 2^{21456155640528} is an apocalyptic number.

21456155640528 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21456155640528 is an abundant number, since it is smaller than the sum of its proper divisors (51872921712432).

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

21456155640528 is a wasteful number, since it uses less digits than its factorization.

21456155640528 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11487394 (or 11487385 counting only the distinct ones).

The product of its (nonzero) digits is 11520000, while the sum is 54.

The spelling of 21456155640528 in words is "twenty-one trillion, four hundred fifty-six billion, one hundred fifty-five million, six hundred forty thousand, five hundred twenty-eight".