137986639 has 4 divisors (see below), whose sum is σ = 157699024. Its totient is φ = 118274256.

The previous prime is 137986633. The next prime is 137986661. The reversal of 137986639 is 936689731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936689731 = 41 ⋅22846091.

It is a cyclic number.

It is not a de Polignac number, because 137986639 - 2³ = 137986631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137986631) 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, 9856182 + ... + 9856195.

It is an arithmetic number, because the mean of its divisors is an integer number (39424756).

Almost surely, 2^137986639 is an apocalyptic number.

137986639 is a deficient number, since it is larger than the sum of its proper divisors (19712385).

137986639 is an equidigital number, since it uses as much as digits as its factorization.

137986639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19712384.

The product of its digits is 1469664, while the sum is 52.

The square root of 137986639 is about 11746.7714287799. The cubic root of 137986639 is about 516.7482471711.

The spelling of 137986639 in words is "one hundred thirty-seven million, nine hundred eighty-six thousand, six hundred thirty-nine".