13520639 has 4 divisors (see below), whose sum is σ = 14749800. Its totient is φ = 12291480.

The previous prime is 13520603. The next prime is 13520653. The reversal of 13520639 is 93602531.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 13520639 - 2⁸ = 13520383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13520659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 614564 + ... + 614585.

It is an arithmetic number, because the mean of its divisors is an integer number (3687450).

Almost surely, 2^13520639 is an apocalyptic number.

13520639 is a deficient number, since it is larger than the sum of its proper divisors (1229161).

13520639 is a wasteful number, since it uses less digits than its factorization.

13520639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1229160.

The product of its (nonzero) digits is 4860, while the sum is 29.

The square root of 13520639 is about 3677.0421536882. The cubic root of 13520639 is about 238.2314381234.

The spelling of 13520639 in words is "thirteen million, five hundred twenty thousand, six hundred thirty-nine".