18921771164 has 6 divisors (see below), whose sum is σ = 33113099544. Its totient is φ = 9460885580.

The previous prime is 18921771139. The next prime is 18921771221. The reversal of 18921771164 is 46117712981.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2365221392 + ... + 2365221399.

It is an arithmetic number, because the mean of its divisors is an integer number (5518849924).

Almost surely, 2^18921771164 is an apocalyptic number.

It is an amenable number.

18921771164 is a deficient number, since it is larger than the sum of its proper divisors (14191328380).

18921771164 is a wasteful number, since it uses less digits than its factorization.

18921771164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4730442795 (or 4730442793 counting only the distinct ones).

The product of its digits is 169344, while the sum is 47.

The spelling of 18921771164 in words is "eighteen billion, nine hundred twenty-one million, seven hundred seventy-one thousand, one hundred sixty-four".