31212740 has 24 divisors (see below), whose sum is σ = 70589400. Its totient is φ = 11524608.

The previous prime is 31212721. The next prime is 31212743. The reversal of 31212740 is 4721213.

It can be written as a sum of positive squares in 4 ways, for example, as 5345344 + 25867396 = 2312^2 + 5086^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (31212743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59765 + ... + 60284.

It is an arithmetic number, because the mean of its divisors is an integer number (2941225).

Almost surely, 2^31212740 is an apocalyptic number.

It is an amenable number.

31212740 is an abundant number, since it is smaller than the sum of its proper divisors (39376660).

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

31212740 is a wasteful number, since it uses less digits than its factorization.

31212740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120071 (or 120069 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 31212740 is about 5586.8363140511. The cubic root of 31212740 is about 314.8550269314.

Adding to 31212740 its reverse (4721213), we get a palindrome (35933953).

The spelling of 31212740 in words is "thirty-one million, two hundred twelve thousand, seven hundred forty".