13791521 has 2 divisors, whose sum is σ = 13791522. Its totient is φ = 13791520.

The previous prime is 13791517. The next prime is 13791523. The reversal of 13791521 is 12519731.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12503296 + 1288225 = 3536^2 + 1135^2 .

It is a cyclic number.

It is not a de Polignac number, because 13791521 - 2² = 13791517 is a prime.

Together with 13791523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (13791523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6895760 + 6895761.

It is an arithmetic number, because the mean of its divisors is an integer number (6895761).

Almost surely, 2^13791521 is an apocalyptic number.

It is an amenable number.

13791521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13791521 is an equidigital number, since it uses as much as digits as its factorization.

13791521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1890, while the sum is 29.

The square root of 13791521 is about 3713.6937138111. The cubic root of 13791521 is about 239.8118954321.

The spelling of 13791521 in words is "thirteen million, seven hundred ninety-one thousand, five hundred twenty-one".