81079200978 has 16 divisors (see below), whose sum is σ = 164379750816. Its totient is φ = 26656175520.

The previous prime is 81079200919. The next prime is 81079201013. The reversal of 81079200978 is 87900297018.

It is a self number, because there is not a number n which added to its sum of digits gives 81079200978.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 92555728 + ... + 92556603.

It is an arithmetic number, because the mean of its divisors is an integer number (10273734426).

Almost surely, 2^81079200978 is an apocalyptic number.

81079200978 is an abundant number, since it is smaller than the sum of its proper divisors (83300549838).

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

81079200978 is a wasteful number, since it uses less digits than its factorization.

81079200978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185112409.

The product of its (nonzero) digits is 508032, while the sum is 51.

The spelling of 81079200978 in words is "eighty-one billion, seventy-nine million, two hundred thousand, nine hundred seventy-eight".