13920509 has 2 divisors, whose sum is σ = 13920510. Its totient is φ = 13920508.

The previous prime is 13920479. The next prime is 13920541. The reversal of 13920509 is 90502931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8265625 + 5654884 = 2875^2 + 2378^2 .

It is an emirp because it is prime and its reverse (90502931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13920509 - 2²⁰ = 12871933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13922509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6960254 + 6960255.

It is an arithmetic number, because the mean of its divisors is an integer number (6960255).

Almost surely, 2^13920509 is an apocalyptic number.

It is an amenable number.

13920509 is a deficient number, since it is larger than the sum of its proper divisors (1).

13920509 is an equidigital number, since it uses as much as digits as its factorization.

13920509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2430, while the sum is 29.

The square root of 13920509 is about 3731.0198337720. The cubic root of 13920509 is about 240.5572064934.

The spelling of 13920509 in words is "thirteen million, nine hundred twenty thousand, five hundred nine".