18645319693 has 32 divisors (see below), whose sum is σ = 25061363712. Its totient is φ = 13396708800.

The previous prime is 18645319681. The next prime is 18645319697. The reversal of 18645319693 is 39691354681.

It is a cyclic number.

It is not a de Polignac number, because 18645319693 - 2⁵ = 18645319661 is a prime.

It is a super-2 number, since 2×18645319693² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18645319697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 962380 + ... + 981562.

It is an arithmetic number, because the mean of its divisors is an integer number (783167616).

Almost surely, 2^18645319693 is an apocalyptic number.

18645319693 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18645319693 is a deficient number, since it is larger than the sum of its proper divisors (6416044019).

18645319693 is a wasteful number, since it uses less digits than its factorization.

18645319693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20185.

The product of its digits is 4199040, while the sum is 55.

The spelling of 18645319693 in words is "eighteen billion, six hundred forty-five million, three hundred nineteen thousand, six hundred ninety-three".