18005951939 has 8 divisors (see below), whose sum is σ = 19014194640. Its totient is φ = 17003765376.

The previous prime is 18005951927. The next prime is 18005951941. The reversal of 18005951939 is 93915950081.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18005951939 - 2²⁰ = 18004903363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18005951989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1507922 + ... + 1519815.

It is an arithmetic number, because the mean of its divisors is an integer number (2376774330).

Almost surely, 2^18005951939 is an apocalyptic number.

18005951939 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

18005951939 is a deficient number, since it is larger than the sum of its proper divisors (1008242701).

18005951939 is a wasteful number, since it uses less digits than its factorization.

18005951939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3028069.

The product of its (nonzero) digits is 437400, while the sum is 50.

The spelling of 18005951939 in words is "eighteen billion, five million, nine hundred fifty-one thousand, nine hundred thirty-nine".