139725531 has 12 divisors (see below), whose sum is σ = 220173720. Its totient is φ = 84682080.

The previous prime is 139725497. The next prime is 139725539. The reversal of 139725531 is 135527931.

139725531 is a `hidden beast` number, since 1 + 39 + 72 + 553 + 1 = 666.

It is not a de Polignac number, because 139725531 - 2⁷ = 139725403 is a prime.

It is a super-2 number, since 2×139725531² = 39046448026463922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (139725539) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 705586 + ... + 705783.

It is an arithmetic number, because the mean of its divisors is an integer number (18347810).

Almost surely, 2^139725531 is an apocalyptic number.

139725531 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

139725531 is a deficient number, since it is larger than the sum of its proper divisors (80448189).

139725531 is a wasteful number, since it uses less digits than its factorization.

139725531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1411386 (or 1411383 counting only the distinct ones).

The product of its digits is 28350, while the sum is 36.

The square root of 139725531 is about 11820.5554438021. Note that the first 3 decimals coincide. The cubic root of 139725531 is about 518.9098599398.

It can be divided in two parts, 13972 and 5531, that added together give a triangular number (19503 = T₁₉₇).

The spelling of 139725531 in words is "one hundred thirty-nine million, seven hundred twenty-five thousand, five hundred thirty-one".