13021391 has 2 divisors, whose sum is σ = 13021392. Its totient is φ = 13021390.

The previous prime is 13021387. The next prime is 13021399. The reversal of 13021391 is 19312031.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 13021391 - 2² = 13021387 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13021399) 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, 6510695 + 6510696.

It is an arithmetic number, because the mean of its divisors is an integer number (6510696).

Almost surely, 2^13021391 is an apocalyptic number.

13021391 is a deficient number, since it is larger than the sum of its proper divisors (1).

13021391 is an equidigital number, since it uses as much as digits as its factorization.

13021391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 13021391 is about 3608.5164541678. The cubic root of 13021391 is about 235.2623657926.

The spelling of 13021391 in words is "thirteen million, twenty-one thousand, three hundred ninety-one".