31312818 has 40 divisors (see below), whose sum is σ = 70514928. Its totient is φ = 10385496.

The previous prime is 31312769. The next prime is 31312823. The reversal of 31312818 is 81821313.

It is a super-2 number, since 2×31312818² = 1960985142202248, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 31312791 and 31312800.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 45505 + ... + 46187.

Almost surely, 2^31312818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31312818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35257464).

31312818 is an abundant number, since it is smaller than the sum of its proper divisors (39202110).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31312818 is a wasteful number, since it uses less digits than its factorization.

31312818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980 (or 971 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 31312818 is about 5595.7857357122. The cubic root of 31312818 is about 315.1911764667.

It can be divided in two parts, 313 and 12818, that added together give a palindrome (13131).

The spelling of 31312818 in words is "thirty-one million, three hundred twelve thousand, eight hundred eighteen".