31988379138 has 64 divisors (see below), whose sum is σ = 70656430080. Its totient is φ = 9615412800.

The previous prime is 31988379133. The next prime is 31988379149. The reversal of 31988379138 is 83197388913.

It is not an unprimeable number, because it can be changed into a prime (31988379133) 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 31 ways as a sum of consecutive naturals, for example, 141381 + ... + 289767.

It is an arithmetic number, because the mean of its divisors is an integer number (1104006720).

Almost surely, 2^31988379138 is an apocalyptic number.

31988379138 is a gapful number since it is divisible by the number (38) formed by its first and last digit.

31988379138 is an abundant number, since it is smaller than the sum of its proper divisors (38668050942).

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

31988379138 is a wasteful number, since it uses less digits than its factorization.

31988379138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148503.

The product of its digits is 7838208, while the sum is 60.

The spelling of 31988379138 in words is "thirty-one billion, nine hundred eighty-eight million, three hundred seventy-nine thousand, one hundred thirty-eight".