13597721 has 2 divisors, whose sum is σ = 13597722. Its totient is φ = 13597720.

The previous prime is 13597699. The next prime is 13597729. The reversal of 13597721 is 12779531.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13579225 + 18496 = 3685^2 + 136^2 .

It is an emirp because it is prime and its reverse (12779531) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13597721 - 2⁶ = 13597657 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (13597729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6798860 + 6798861.

It is an arithmetic number, because the mean of its divisors is an integer number (6798861).

Almost surely, 2^13597721 is an apocalyptic number.

It is an amenable number.

13597721 is a deficient number, since it is larger than the sum of its proper divisors (1).

13597721 is an equidigital number, since it uses as much as digits as its factorization.

13597721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13230, while the sum is 35.

The square root of 13597721 is about 3687.5087796506. The cubic root of 13597721 is about 238.6833045613.

The spelling of 13597721 in words is "thirteen million, five hundred ninety-seven thousand, seven hundred twenty-one".