13161991 has 2 divisors, whose sum is σ = 13161992. Its totient is φ = 13161990.

The previous prime is 13161983. The next prime is 13162043. The reversal of 13161991 is 19916131.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 13161991 - 2³ = 13161983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13161931) 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, 6580995 + 6580996.

It is an arithmetic number, because the mean of its divisors is an integer number (6580996).

Almost surely, 2^13161991 is an apocalyptic number.

13161991 is a deficient number, since it is larger than the sum of its proper divisors (1).

13161991 is an equidigital number, since it uses as much as digits as its factorization.

13161991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1458, while the sum is 31.

The square root of 13161991 is about 3627.9458375229. The cubic root of 13161991 is about 236.1060939721.

The spelling of 13161991 in words is "thirteen million, one hundred sixty-one thousand, nine hundred ninety-one".