13166521 has 2 divisors, whose sum is σ = 13166522. Its totient is φ = 13166520.

The previous prime is 13166519. The next prime is 13166567. The reversal of 13166521 is 12566131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7502121 + 5664400 = 2739^2 + 2380^2 .

It is a cyclic number.

It is not a de Polignac number, because 13166521 - 2¹ = 13166519 is a prime.

Together with 13166519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (13166581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6583260 + 6583261.

It is an arithmetic number, because the mean of its divisors is an integer number (6583261).

Almost surely, 2^13166521 is an apocalyptic number.

It is an amenable number.

13166521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13166521 is an equidigital number, since it uses as much as digits as its factorization.

13166521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 25.

The square root of 13166521 is about 3628.5701040493. The cubic root of 13166521 is about 236.1331779678.

The spelling of 13166521 in words is "thirteen million, one hundred sixty-six thousand, five hundred twenty-one".