31623140 has 12 divisors (see below), whose sum is σ = 66408636. Its totient is φ = 12649248.

The previous prime is 31623121. The next prime is 31623167. The reversal of 31623140 is 4132613.

It can be written as a sum of positive squares in 2 ways, for example, as 5837056 + 25786084 = 2416^2 + 5078^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1581157 = 31623140 / (3 + 1 + 6 + 2 + 3 + 1 + 4 + 0).

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 3 ways as a sum of consecutive naturals, for example, 790559 + ... + 790598.

It is an arithmetic number, because the mean of its divisors is an integer number (5534053).

Almost surely, 2^31623140 is an apocalyptic number.

It is an amenable number.

31623140 is an abundant number, since it is smaller than the sum of its proper divisors (34785496).

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

31623140 is a wasteful number, since it uses less digits than its factorization.

31623140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1581166 (or 1581164 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 31623140 is about 5623.4455629978. The cubic root of 31623140 is about 316.2289773399.

Adding to 31623140 its reverse (4132613), we get a palindrome (35755753).

The spelling of 31623140 in words is "thirty-one million, six hundred twenty-three thousand, one hundred forty".