81756448862913 has 96 divisors (see below), whose sum is σ = 142718824385280. Its totient is φ = 44487501189120.

The previous prime is 81756448862897. The next prime is 81756448862927. The reversal of 81756448862913 is 31926884465718.

81756448862913 is a `hidden beast` number, since 8 + 1 + 7 + 56 + 4 + 488 + 6 + 2 + 91 + 3 = 666.

It is not a de Polignac number, because 81756448862913 - 2⁴ = 81756448862897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81756444862913) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11607253 + ... + 17269661.

It is an arithmetic number, because the mean of its divisors is an integer number (1486654420680).

Almost surely, 2^{81756448862913} is an apocalyptic number.

It is an amenable number.

81756448862913 is a deficient number, since it is larger than the sum of its proper divisors (60962375522367).

81756448862913 is a wasteful number, since it uses less digits than its factorization.

81756448862913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5662839 (or 5662836 counting only the distinct ones).

The product of its digits is 557383680, while the sum is 72.

The spelling of 81756448862913 in words is "eighty-one trillion, seven hundred fifty-six billion, four hundred forty-eight million, eight hundred sixty-two thousand, nine hundred thirteen".