13991507 has 2 divisors, whose sum is σ = 13991508. Its totient is φ = 13991506.

The previous prime is 13991503. The next prime is 13991533. The reversal of 13991507 is 70519931.

It is a weak prime.

It is an emirp because it is prime and its reverse (70519931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13991507 - 2² = 13991503 is a prime.

It is not a weakly prime, because it can be changed into another prime (13991501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6995753 + 6995754.

It is an arithmetic number, because the mean of its divisors is an integer number (6995754).

Almost surely, 2^13991507 is an apocalyptic number.

13991507 is a deficient number, since it is larger than the sum of its proper divisors (1).

13991507 is an equidigital number, since it uses as much as digits as its factorization.

13991507 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8505, while the sum is 35.

The square root of 13991507 is about 3740.5222897344. The cubic root of 13991507 is about 240.9654800393.

The spelling of 13991507 in words is "thirteen million, nine hundred ninety-one thousand, five hundred seven".