18791339881 has 4 divisors (see below), whose sum is σ = 18792784512. Its totient is φ = 18789895252.

The previous prime is 18791339869. The next prime is 18791339909. The reversal of 18791339881 is 18893319781.

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 a cyclic number.

It is not a de Polignac number, because 18791339881 - 2¹⁷ = 18791208809 is a prime.

It is a super-2 number, since 2×18791339881² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18791339681) 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, 702625 + ... + 728878.

It is an arithmetic number, because the mean of its divisors is an integer number (4698196128).

Almost surely, 2^18791339881 is an apocalyptic number.

It is an amenable number.

18791339881 is a deficient number, since it is larger than the sum of its proper divisors (1444631).

18791339881 is a wasteful number, since it uses less digits than its factorization.

18791339881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1444630.

The product of its digits is 2612736, while the sum is 58.

The spelling of 18791339881 in words is "eighteen billion, seven hundred ninety-one million, three hundred thirty-nine thousand, eight hundred eighty-one".