13391621 has 2 divisors, whose sum is σ = 13391622. Its totient is φ = 13391620.

The previous prime is 13391551. The next prime is 13391639. The reversal of 13391621 is 12619331.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13060996 + 330625 = 3614^2 + 575^2 .

It is a cyclic number.

It is not a de Polignac number, because 13391621 - 2¹⁴ = 13375237 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13391641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6695810 + 6695811.

It is an arithmetic number, because the mean of its divisors is an integer number (6695811).

Almost surely, 2^13391621 is an apocalyptic number.

It is an amenable number.

13391621 is a deficient number, since it is larger than the sum of its proper divisors (1).

13391621 is an equidigital number, since it uses as much as digits as its factorization.

13391621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 972, while the sum is 26.

The square root of 13391621 is about 3659.4563803931. The cubic root of 13391621 is about 237.4712563552.

The spelling of 13391621 in words is "thirteen million, three hundred ninety-one thousand, six hundred twenty-one".