18391158644 has 24 divisors (see below), whose sum is σ = 32961911136. Its totient is φ = 8975772000.

The previous prime is 18391158641. The next prime is 18391158677. The reversal of 18391158644 is 44685119381.

It is a junction number, because it is equal to n+sod(n) for n = 18391158592 and 18391158601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18391158641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 255722 + ... + 319649.

It is an arithmetic number, because the mean of its divisors is an integer number (1373412964).

Almost surely, 2^18391158644 is an apocalyptic number.

It is an amenable number.

18391158644 is a deficient number, since it is larger than the sum of its proper divisors (14570752492).

18391158644 is a wasteful number, since it uses less digits than its factorization.

18391158644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575567 (or 575565 counting only the distinct ones).

The product of its digits is 829440, while the sum is 50.

The spelling of 18391158644 in words is "eighteen billion, three hundred ninety-one million, one hundred fifty-eight thousand, six hundred forty-four".