18020073881 has 4 divisors (see below), whose sum is σ = 18020491572. Its totient is φ = 18019656192.

The previous prime is 18020073859. The next prime is 18020073889. The reversal of 18020073881 is 18837002081.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14140777225 + 3879296656 = 118915^2 + 62284^2 .

It is a cyclic number.

It is not a de Polignac number, because 18020073881 - 2¹⁰ = 18020072857 is a prime.

It is a super-2 number, since 2×18020073881² (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 (18020073889) 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, 135560 + ... + 233273.

It is an arithmetic number, because the mean of its divisors is an integer number (4505122893).

Almost surely, 2^18020073881 is an apocalyptic number.

It is an amenable number.

18020073881 is a deficient number, since it is larger than the sum of its proper divisors (417691).

18020073881 is an equidigital number, since it uses as much as digits as its factorization.

18020073881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417690.

The product of its (nonzero) digits is 21504, while the sum is 38.

The spelling of 18020073881 in words is "eighteen billion, twenty million, seventy-three thousand, eight hundred eighty-one".