31818518185 has 4 divisors (see below), whose sum is σ = 38182221828. Its totient is φ = 25454814544.

The previous prime is 31818518167. The next prime is 31818518189. The reversal of 31818518185 is 58181581813.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58181581813 = 17 ⋅3422445989.

It can be written as a sum of positive squares in 2 ways, for example, as 13128347241 + 18690170944 = 114579^2 + 136712^2 .

It is a cyclic number.

It is not a de Polignac number, because 31818518185 - 2⁷ = 31818518057 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31818518189) 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, 3181851814 + ... + 3181851823.

It is an arithmetic number, because the mean of its divisors is an integer number (9545555457).

Almost surely, 2^31818518185 is an apocalyptic number.

It is an amenable number.

31818518185 is a deficient number, since it is larger than the sum of its proper divisors (6363703643).

31818518185 is an equidigital number, since it uses as much as digits as its factorization.

31818518185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6363703642.

The product of its digits is 307200, while the sum is 49.

The spelling of 31818518185 in words is "thirty-one billion, eight hundred eighteen million, five hundred eighteen thousand, one hundred eighty-five".