13521397 has 2 divisors, whose sum is σ = 13521398. Its totient is φ = 13521396.

The previous prime is 13521373. The next prime is 13521419. The reversal of 13521397 is 79312531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11229201 + 2292196 = 3351^2 + 1514^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13521397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13521367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6760698 + 6760699.

It is an arithmetic number, because the mean of its divisors is an integer number (6760699).

Almost surely, 2^13521397 is an apocalyptic number.

It is an amenable number.

13521397 is a deficient number, since it is larger than the sum of its proper divisors (1).

13521397 is an equidigital number, since it uses as much as digits as its factorization.

13521397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5670, while the sum is 31.

The square root of 13521397 is about 3677.1452242195. The cubic root of 13521397 is about 238.2358899854.

The spelling of 13521397 in words is "thirteen million, five hundred twenty-one thousand, three hundred ninety-seven".