18647560909 has 2 divisors, whose sum is σ = 18647560910. Its totient is φ = 18647560908.

The previous prime is 18647560903. The next prime is 18647560927. The reversal of 18647560909 is 90906574681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16617788100 + 2029772809 = 128910^2 + 45053^2 .

It is a cyclic number.

It is not a de Polignac number, because 18647560909 - 2²¹ = 18645463757 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18647560909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18647560903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9323780454 + 9323780455.

It is an arithmetic number, because the mean of its divisors is an integer number (9323780455).

Almost surely, 2^18647560909 is an apocalyptic number.

It is an amenable number.

18647560909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18647560909 is an equidigital number, since it uses as much as digits as its factorization.

18647560909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3265920, while the sum is 55.

The spelling of 18647560909 in words is "eighteen billion, six hundred forty-seven million, five hundred sixty thousand, nine hundred nine".