18720857711 has 4 divisors (see below), whose sum is σ = 18780669072. Its totient is φ = 18661046352.

The previous prime is 18720857677. The next prime is 18720857731. The reversal of 18720857711 is 11775802781.

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

It is a cyclic number.

It is not a de Polignac number, because 18720857711 - 2¹⁸ = 18720595567 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18720857731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29905211 + ... + 29905836.

It is an arithmetic number, because the mean of its divisors is an integer number (4695167268).

Almost surely, 2^18720857711 is an apocalyptic number.

18720857711 is a deficient number, since it is larger than the sum of its proper divisors (59811361).

18720857711 is an equidigital number, since it uses as much as digits as its factorization.

18720857711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59811360.

The product of its (nonzero) digits is 219520, while the sum is 47.

The spelling of 18720857711 in words is "eighteen billion, seven hundred twenty million, eight hundred fifty-seven thousand, seven hundred eleven".