39931951231091 has 4 divisors (see below), whose sum is σ = 40074057819384. Its totient is φ = 39789844642800.

The previous prime is 39931951231063. The next prime is 39931951231147. The reversal of 39931951231091 is 19013215913993.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39931951231091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39931951231001) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 71053293725 + ... + 71053294286.

It is an arithmetic number, because the mean of its divisors is an integer number (10018514454846).

Almost surely, 2^{39931951231091} is an apocalyptic number.

39931951231091 is a deficient number, since it is larger than the sum of its proper divisors (142106588293).

39931951231091 is a wasteful number, since it uses less digits than its factorization.

39931951231091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142106588292.

The product of its (nonzero) digits is 1771470, while the sum is 56.

The spelling of 39931951231091 in words is "thirty-nine trillion, nine hundred thirty-one billion, nine hundred fifty-one million, two hundred thirty-one thousand, ninety-one".