13639531 has 2 divisors, whose sum is σ = 13639532. Its totient is φ = 13639530.

The previous prime is 13639523. The next prime is 13639543. The reversal of 13639531 is 13593631.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 13639531 - 2³ = 13639523 is a prime.

It is a super-2 number, since 2×13639531² = 372073611799922, which contains 22 as substring.

It is a Chen prime.

It is a nialpdrome in base 11.

It is a zygodrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 13639493 and 13639502.

It is not a weakly prime, because it can be changed into another prime (13639231) 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, 6819765 + 6819766.

It is an arithmetic number, because the mean of its divisors is an integer number (6819766).

Almost surely, 2^13639531 is an apocalyptic number.

13639531 is a deficient number, since it is larger than the sum of its proper divisors (1).

13639531 is an equidigital number, since it uses as much as digits as its factorization.

13639531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7290, while the sum is 31.

The square root of 13639531 is about 3693.1735675432. The cubic root of 13639531 is about 238.9276871383.

The spelling of 13639531 in words is "thirteen million, six hundred thirty-nine thousand, five hundred thirty-one".