21576455490897 has 12 divisors (see below), whose sum is σ = 31176488437380. Its totient is φ = 14379458811648.

The previous prime is 21576455490871. The next prime is 21576455490913. The reversal of 21576455490897 is 79809455467512.

21576455490897 is a `hidden beast` number, since 2 + 1 + 5 + 7 + 6 + 4 + 55 + 490 + 89 + 7 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 9713500989201 + 11862954501696 = 3116649^2 + 3444264^2 .

It is not a de Polignac number, because 21576455490897 - 2⁷ = 21576455490769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21576455490827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 403709208 + ... + 403762649.

It is an arithmetic number, because the mean of its divisors is an integer number (2598040703115).

Almost surely, 2^{21576455490897} is an apocalyptic number.

It is an amenable number.

21576455490897 is a deficient number, since it is larger than the sum of its proper divisors (9600032946483).

21576455490897 is a wasteful number, since it uses less digits than its factorization.

21576455490897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807474832 (or 807474829 counting only the distinct ones).

The product of its (nonzero) digits is 762048000, while the sum is 72.

The spelling of 21576455490897 in words is "twenty-one trillion, five hundred seventy-six billion, four hundred fifty-five million, four hundred ninety thousand, eight hundred ninety-seven".