139709231 has 2 divisors, whose sum is σ = 139709232. Its totient is φ = 139709230.

The previous prime is 139709221. The next prime is 139709243. The reversal of 139709231 is 132907931.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139709231 is a prime.

It is a super-2 number, since 2×139709231² = 39037338453222722, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 139709191 and 139709200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139709201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69854615 + 69854616.

It is an arithmetic number, because the mean of its divisors is an integer number (69854616).

Almost surely, 2^139709231 is an apocalyptic number.

139709231 is a deficient number, since it is larger than the sum of its proper divisors (1).

139709231 is an equidigital number, since it uses as much as digits as its factorization.

139709231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10206, while the sum is 35.

The square root of 139709231 is about 11819.8659467864. The cubic root of 139709231 is about 518.8896809513.

The spelling of 139709231 in words is "one hundred thirty-nine million, seven hundred nine thousand, two hundred thirty-one".