686990139 has 8 divisors (see below), whose sum is σ = 999258432. Its totient is φ = 416357640.

The previous prime is 686990123. The next prime is 686990177. The reversal of 686990139 is 931099686.

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

It is not a de Polignac number, because 686990139 - 2⁴ = 686990123 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 686990091 and 686990100.

It is not an unprimeable number, because it can be changed into a prime (686990189) 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, 10408909 + ... + 10408974.

It is an arithmetic number, because the mean of its divisors is an integer number (124907304).

Almost surely, 2^686990139 is an apocalyptic number.

686990139 is a deficient number, since it is larger than the sum of its proper divisors (312268293).

686990139 is a wasteful number, since it uses less digits than its factorization.

686990139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20817897.

The product of its (nonzero) digits is 629856, while the sum is 51.

The square root of 686990139 is about 26210.4967331792. The cubic root of 686990139 is about 882.3688496397.

The spelling of 686990139 in words is "six hundred eighty-six million, nine hundred ninety thousand, one hundred thirty-nine".