18420943686 has 36 divisors (see below), whose sum is σ = 37445251788. Its totient is φ = 6041354088.

The previous prime is 18420943661. The next prime is 18420943711. The reversal of 18420943686 is 68634902481.

It is an interprime number because it is at equal distance from previous prime (18420943661) and next prime (18420943711).

It is a Curzon number.

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 in 17 ways as a sum of consecutive naturals, for example, 22274005 + ... + 22274831.

It is an arithmetic number, because the mean of its divisors is an integer number (1040145883).

Almost surely, 2^18420943686 is an apocalyptic number.

18420943686 is an abundant number, since it is smaller than the sum of its proper divisors (19024308102).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18420943686 is an frugal number, since it uses more digits than its factorization.

18420943686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1793 (or 899 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 51.

The spelling of 18420943686 in words is "eighteen billion, four hundred twenty million, nine hundred forty-three thousand, six hundred eighty-six".