18838840731 has 4 divisors (see below), whose sum is σ = 25118454312. Its totient is φ = 12559227152.

The previous prime is 18838840729. The next prime is 18838840739. The reversal of 18838840731 is 13704883881.

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

It is a cyclic number.

It is not a de Polignac number, because 18838840731 - 2¹ = 18838840729 is a prime.

It is a super-2 number, since 2×18838840731² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18838840739) 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, 3139806786 + ... + 3139806791.

It is an arithmetic number, because the mean of its divisors is an integer number (6279613578).

Almost surely, 2^18838840731 is an apocalyptic number.

18838840731 is a deficient number, since it is larger than the sum of its proper divisors (6279613581).

18838840731 is an equidigital number, since it uses as much as digits as its factorization.

18838840731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6279613580.

The product of its (nonzero) digits is 1032192, while the sum is 51.

The spelling of 18838840731 in words is "eighteen billion, eight hundred thirty-eight million, eight hundred forty thousand, seven hundred thirty-one".