18644120986 has 4 divisors (see below), whose sum is σ = 27966181482. Its totient is φ = 9322060492.

The previous prime is 18644120939. The next prime is 18644121007. The reversal of 18644120986 is 68902144681.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 17451731025 + 1192389961 = 132105^2 + 34531^2 .

It is a super-2 number, since 2×18644120986² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4661030245 + ... + 4661030248.

Almost surely, 2^18644120986 is an apocalyptic number.

18644120986 is a deficient number, since it is larger than the sum of its proper divisors (9322060496).

18644120986 is an equidigital number, since it uses as much as digits as its factorization.

18644120986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9322060495.

The product of its (nonzero) digits is 663552, while the sum is 49.

The spelling of 18644120986 in words is "eighteen billion, six hundred forty-four million, one hundred twenty thousand, nine hundred eighty-six".