18507913 has 2 divisors, whose sum is σ = 18507914. Its totient is φ = 18507912.

The previous prime is 18507911. The next prime is 18507941. The reversal of 18507913 is 31970581.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18088009 + 419904 = 4253^2 + 648^2 .

It is an emirp because it is prime and its reverse (31970581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18507913 - 2¹ = 18507911 is a prime.

Together with 18507911, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18507911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9253956 + 9253957.

It is an arithmetic number, because the mean of its divisors is an integer number (9253957).

Almost surely, 2^18507913 is an apocalyptic number.

It is an amenable number.

18507913 is a deficient number, since it is larger than the sum of its proper divisors (1).

18507913 is an equidigital number, since it uses as much as digits as its factorization.

18507913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7560, while the sum is 34.

The square root of 18507913 is about 4302.0824027440. The cubic root of 18507913 is about 264.5163267164.

The spelling of 18507913 in words is "eighteen million, five hundred seven thousand, nine hundred thirteen".