139555531 has 2 divisors, whose sum is σ = 139555532. Its totient is φ = 139555530.

The previous prime is 139555529. The next prime is 139555553. The reversal of 139555531 is 135555931.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 139555531 - 2¹ = 139555529 is a prime.

It is a super-2 number, since 2×139555531² = 38951492465383922, which contains 22 as substring.

Together with 139555529, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (139555561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69777765 + 69777766.

It is an arithmetic number, because the mean of its divisors is an integer number (69777766).

Almost surely, 2^139555531 is an apocalyptic number.

139555531 is a deficient number, since it is larger than the sum of its proper divisors (1).

139555531 is an equidigital number, since it uses as much as digits as its factorization.

139555531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 50625, while the sum is 37.

The square root of 139555531 is about 11813.3623918002. The cubic root of 139555531 is about 518.6993270094.

The spelling of 139555531 in words is "one hundred thirty-nine million, five hundred fifty-five thousand, five hundred thirty-one".