18615680617 has 4 divisors (see below), whose sum is σ = 19011758976. Its totient is φ = 18219602260.

The previous prime is 18615680599. The next prime is 18615680627. The reversal of 18615680617 is 71608651681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18615680617 - 2¹¹ = 18615678569 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18615680627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198039109 + ... + 198039202.

It is an arithmetic number, because the mean of its divisors is an integer number (4752939744).

Almost surely, 2^18615680617 is an apocalyptic number.

It is an amenable number.

18615680617 is a deficient number, since it is larger than the sum of its proper divisors (396078359).

18615680617 is an equidigital number, since it uses as much as digits as its factorization.

18615680617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396078358.

The product of its (nonzero) digits is 483840, while the sum is 49.

The spelling of 18615680617 in words is "eighteen billion, six hundred fifteen million, six hundred eighty thousand, six hundred seventeen".