13315921 has 2 divisors, whose sum is σ = 13315922. Its totient is φ = 13315920.

The previous prime is 13315909. The next prime is 13315931. The reversal of 13315921 is 12951331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9235521 + 4080400 = 3039^2 + 2020^2 .

It is a cyclic number.

It is not a de Polignac number, because 13315921 - 2⁵ = 13315889 is a prime.

It is a zygodrome in base 7.

It is not a weakly prime, because it can be changed into another prime (13315931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6657960 + 6657961.

It is an arithmetic number, because the mean of its divisors is an integer number (6657961).

Almost surely, 2^13315921 is an apocalyptic number.

It is an amenable number.

13315921 is a deficient number, since it is larger than the sum of its proper divisors (1).

13315921 is an equidigital number, since it uses as much as digits as its factorization.

13315921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 810, while the sum is 25.

The square root of 13315921 is about 3649.0986558327. The cubic root of 13315921 is about 237.0229523131.

The spelling of 13315921 in words is "thirteen million, three hundred fifteen thousand, nine hundred twenty-one".