81570488407518 has 16 divisors (see below), whose sum is σ = 177971974707456. Its totient is φ = 24718329820440.

The previous prime is 81570488407511. The next prime is 81570488407523.

81570488407518 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (66), and also a Moran number because the ratio is a prime number: 1235916491023 = 81570488407518 / (8 + 1 + 5 + 7 + 0 + 4 + 8 + 8 + 4 + 0 + 7 + 5 + 1 + 8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81570488407511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 617958245446 + ... + 617958245577.

It is an arithmetic number, because the mean of its divisors is an integer number (11123248419216).

Almost surely, 2^{81570488407518} is an apocalyptic number.

81570488407518 is an abundant number, since it is smaller than the sum of its proper divisors (96401486299938).

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

81570488407518 is a wasteful number, since it uses less digits than its factorization.

81570488407518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1235916491039.

The product of its (nonzero) digits is 80281600, while the sum is 66.

The spelling of 81570488407518 in words is "eighty-one trillion, five hundred seventy billion, four hundred eighty-eight million, four hundred seven thousand, five hundred eighteen".