31680818 has 16 divisors (see below), whose sum is σ = 52942680. Its totient is φ = 14117376.

The previous prime is 31680799. The next prime is 31680829. The reversal of 31680818 is 81808613.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 15864289 + 15816529 = 3983^2 + 3977^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20255 + ... + 21762.

Almost surely, 2^31680818 is an apocalyptic number.

31680818 is a deficient number, since it is larger than the sum of its proper divisors (21261862).

31680818 is a wasteful number, since it uses less digits than its factorization.

31680818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42061.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 31680818 is about 5628.5715772299. The cubic root of 31680818 is about 316.4211190974.

It can be divided in two parts, 316808 and 18, that multiplied together give a square (5702544 = 2388²).

The spelling of 31680818 in words is "thirty-one million, six hundred eighty thousand, eight hundred eighteen".