18008717047561 has 4 divisors (see below), whose sum is σ = 18008749252624. Its totient is φ = 18008684842500.

The previous prime is 18008717047543. The next prime is 18008717047577. The reversal of 18008717047561 is 16574071780081.

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 18008717047561 - 2⁹ = 18008717047049 is a prime.

It is a super-2 number, since 2×18008717047561² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18008717047511) 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, 15248655 + ... + 16387156.

It is an arithmetic number, because the mean of its divisors is an integer number (4502187313156).

Almost surely, 2^{18008717047561} is an apocalyptic number.

It is an amenable number.

18008717047561 is a deficient number, since it is larger than the sum of its proper divisors (32205063).

18008717047561 is an equidigital number, since it uses as much as digits as its factorization.

18008717047561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32205062.

The product of its (nonzero) digits is 2634240, while the sum is 55.

The spelling of 18008717047561 in words is "eighteen trillion, eight billion, seven hundred seventeen million, forty-seven thousand, five hundred sixty-one".