138991503731 has 4 divisors (see below), whose sum is σ = 139001891952. Its totient is φ = 138981115512.

The previous prime is 138991503713. The next prime is 138991503733. The reversal of 138991503731 is 137305199831.

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

It is a cyclic number.

It is not a de Polignac number, because 138991503731 - 2²⁶ = 138924394867 is a prime.

It is a super-2 number, since 2×138991503731² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138991503731.

It is not an unprimeable number, because it can be changed into a prime (138991503733) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5174015 + ... + 5200808.

It is an arithmetic number, because the mean of its divisors is an integer number (34750472988).

Almost surely, 2^138991503731 is an apocalyptic number.

138991503731 is a deficient number, since it is larger than the sum of its proper divisors (10388221).

138991503731 is a wasteful number, since it uses less digits than its factorization.

138991503731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10388220.

The product of its (nonzero) digits is 612360, while the sum is 50.

The spelling of 138991503731 in words is "one hundred thirty-eight billion, nine hundred ninety-one million, five hundred three thousand, seven hundred thirty-one".