138931061958 has 96 divisors (see below), whose sum is σ = 331855130880. Its totient is φ = 41744548800.

The previous prime is 138931061939. The next prime is 138931061959. The reversal of 138931061958 is 859160139831.

138931061958 is a `hidden beast` number, since 1 + 3 + 8 + 9 + 3 + 10 + 619 + 5 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138931061959) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2051385 + ... + 2118027.

It is an arithmetic number, because the mean of its divisors is an integer number (3456824280).

Almost surely, 2^138931061958 is an apocalyptic number.

138931061958 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 138931061958, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (165927565440).

138931061958 is an abundant number, since it is smaller than the sum of its proper divisors (192924068922).

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

138931061958 is a wasteful number, since it uses less digits than its factorization.

138931061958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66874 (or 66871 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 54.

The spelling of 138931061958 in words is "one hundred thirty-eight billion, nine hundred thirty-one million, sixty-one thousand, nine hundred fifty-eight".