13397981 has 2 divisors, whose sum is σ = 13397982. Its totient is φ = 13397980.

The previous prime is 13397977. The next prime is 13397987. The reversal of 13397981 is 18979331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12996025 + 401956 = 3605^2 + 634^2 .

It is a cyclic number.

It is not a de Polignac number, because 13397981 - 2² = 13397977 is a prime.

It is a super-2 number, since 2×13397981² = 359011789752722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13397987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6698990 + 6698991.

It is an arithmetic number, because the mean of its divisors is an integer number (6698991).

Almost surely, 2^13397981 is an apocalyptic number.

It is an amenable number.

13397981 is a deficient number, since it is larger than the sum of its proper divisors (1).

13397981 is an equidigital number, since it uses as much as digits as its factorization.

13397981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 41.

The square root of 13397981 is about 3660.3252587714. The cubic root of 13397981 is about 237.5088439920.

The spelling of 13397981 in words is "thirteen million, three hundred ninety-seven thousand, nine hundred eighty-one".