81570938465 has 8 divisors (see below), whose sum is σ = 97945298880. Its totient is φ = 65216635632.

The previous prime is 81570938459. The next prime is 81570938479. The reversal of 81570938465 is 56483907518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81570938465 - 2⁶ = 81570938401 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81570938465.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5005445 + ... + 5021714.

It is an arithmetic number, because the mean of its divisors is an integer number (12243162360).

Almost surely, 2^81570938465 is an apocalyptic number.

It is an amenable number.

81570938465 is a deficient number, since it is larger than the sum of its proper divisors (16374360415).

81570938465 is a wasteful number, since it uses less digits than its factorization.

81570938465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10028791.

The product of its (nonzero) digits is 7257600, while the sum is 56.

The spelling of 81570938465 in words is "eighty-one billion, five hundred seventy million, nine hundred thirty-eight thousand, four hundred sixty-five".