18455117566 has 4 divisors (see below), whose sum is σ = 27682676352. Its totient is φ = 9227558782.

The previous prime is 18455117561. The next prime is 18455117599. The reversal of 18455117566 is 66571155481.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18455117561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4613779390 + ... + 4613779393.

It is an arithmetic number, because the mean of its divisors is an integer number (6920669088).

Almost surely, 2^18455117566 is an apocalyptic number.

18455117566 is a deficient number, since it is larger than the sum of its proper divisors (9227558786).

18455117566 is an equidigital number, since it uses as much as digits as its factorization.

18455117566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9227558785.

The product of its digits is 1008000, while the sum is 49.

The spelling of 18455117566 in words is "eighteen billion, four hundred fifty-five million, one hundred seventeen thousand, five hundred sixty-six".