18720777776 has 20 divisors (see below), whose sum is σ = 37156179144. Its totient is φ = 9132086400.

The previous prime is 18720777743. The next prime is 18720777793. The reversal of 18720777776 is 67777702781.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14268230 + ... + 14269541.

Almost surely, 2^18720777776 is an apocalyptic number.

18720777776 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18720777776 is a deficient number, since it is larger than the sum of its proper divisors (18435401368).

18720777776 is a wasteful number, since it uses less digits than its factorization.

18720777776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28537820 (or 28537814 counting only the distinct ones).

The product of its (nonzero) digits is 11294304, while the sum is 59.

The spelling of 18720777776 in words is "eighteen billion, seven hundred twenty million, seven hundred seventy-seven thousand, seven hundred seventy-six".