81079817907 has 32 divisors (see below), whose sum is σ = 121782435840. Its totient is φ = 47537028000.

The previous prime is 81079817893. The next prime is 81079817981. The reversal of 81079817907 is 70971897018.

It is not a de Polignac number, because 81079817907 - 2⁶ = 81079817843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81079815907) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3178032 + ... + 3203442.

It is an arithmetic number, because the mean of its divisors is an integer number (3805701120).

Almost surely, 2^81079817907 is an apocalyptic number.

81079817907 is a deficient number, since it is larger than the sum of its proper divisors (40702617933).

81079817907 is a wasteful number, since it uses less digits than its factorization.

81079817907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28575.

The product of its (nonzero) digits is 1778112, while the sum is 57.

The spelling of 81079817907 in words is "eighty-one billion, seventy-nine million, eight hundred seventeen thousand, nine hundred seven".