18831569961 has 4 divisors (see below), whose sum is σ = 25108759952. Its totient is φ = 12554379972.

The previous prime is 18831569923. The next prime is 18831569971. The reversal of 18831569961 is 16996513881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 18831569961 - 2¹⁰ = 18831568937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18831569971) 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, 3138594991 + ... + 3138594996.

It is an arithmetic number, because the mean of its divisors is an integer number (6277189988).

Almost surely, 2^18831569961 is an apocalyptic number.

It is an amenable number.

18831569961 is a deficient number, since it is larger than the sum of its proper divisors (6277189991).

18831569961 is an equidigital number, since it uses as much as digits as its factorization.

18831569961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6277189990.

The product of its digits is 2799360, while the sum is 57.

The spelling of 18831569961 in words is "eighteen billion, eight hundred thirty-one million, five hundred sixty-nine thousand, nine hundred sixty-one".