13813991 has 2 divisors, whose sum is σ = 13813992. Its totient is φ = 13813990.

The previous prime is 13813963. The next prime is 13813997. The reversal of 13813991 is 19931831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 13813991 - 2⁶ = 13813927 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13813997) 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, 6906995 + 6906996.

It is an arithmetic number, because the mean of its divisors is an integer number (6906996).

Almost surely, 2^13813991 is an apocalyptic number.

13813991 is a deficient number, since it is larger than the sum of its proper divisors (1).

13813991 is an equidigital number, since it uses as much as digits as its factorization.

13813991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5832, while the sum is 35.

The square root of 13813991 is about 3716.7177724439. The cubic root of 13813991 is about 239.9420635615.

The spelling of 13813991 in words is "thirteen million, eight hundred thirteen thousand, nine hundred ninety-one".