139686931 has 8 divisors (see below), whose sum is σ = 142251200. Its totient is φ = 137142720.

The previous prime is 139686923. The next prime is 139687007.

139686931 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 139686931 - 2³ = 139686923 is a prime.

It is a super-2 number, since 2×139686931² = 39024877384397522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139683931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9415 + ... + 19183.

It is an arithmetic number, because the mean of its divisors is an integer number (17781400).

Almost surely, 2^139686931 is an apocalyptic number.

139686931 is a deficient number, since it is larger than the sum of its proper divisors (2564269).

139686931 is an equidigital number, since it uses as much as digits as its factorization.

139686931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10029.

The product of its digits is 209952, while the sum is 46.

The square root of 139686931 is about 11818.9225820292. The cubic root of 139686931 is about 518.8620715717.

The spelling of 139686931 in words is "one hundred thirty-nine million, six hundred eighty-six thousand, nine hundred thirty-one".