18218210931 has 8 divisors (see below), whose sum is σ = 26989942160. Its totient is φ = 12145473936.

The previous prime is 18218210929. The next prime is 18218210953. The reversal of 18218210931 is 13901281281.

It is a happy number.

It is not a de Polignac number, because 18218210931 - 2¹ = 18218210929 is a prime.

It is a super-2 number, since 2×18218210931² (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 (18218280931) 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, 337374250 + ... + 337374303.

It is an arithmetic number, because the mean of its divisors is an integer number (3373742770).

Almost surely, 2^18218210931 is an apocalyptic number.

18218210931 is a deficient number, since it is larger than the sum of its proper divisors (8771731229).

18218210931 is an equidigital number, since it uses as much as digits as its factorization.

18218210931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 674748562 (or 674748556 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The spelling of 18218210931 in words is "eighteen billion, two hundred eighteen million, two hundred ten thousand, nine hundred thirty-one".