81952205678 has 64 divisors (see below), whose sum is σ = 147257450496. Its totient is φ = 33466608000.

The previous prime is 81952205659. The next prime is 81952205693. The reversal of 81952205678 is 87650225918.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34418048 + ... + 34420428.

It is an arithmetic number, because the mean of its divisors is an integer number (2300897664).

Almost surely, 2^81952205678 is an apocalyptic number.

81952205678 is a deficient number, since it is larger than the sum of its proper divisors (65305244818).

81952205678 is a wasteful number, since it uses less digits than its factorization.

81952205678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3609.

The product of its (nonzero) digits is 2419200, while the sum is 53.

The spelling of 81952205678 in words is "eighty-one billion, nine hundred fifty-two million, two hundred five thousand, six hundred seventy-eight".