31013440 has 56 divisors (see below), whose sum is σ = 78208632. Its totient is φ = 11673600.

The previous prime is 31013431. The next prime is 31013461. The reversal of 31013440 is 4431013.

It can be written as a sum of positive squares in 4 ways, for example, as 11723776 + 19289664 = 3424^2 + 4392^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

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, 2590 + ... + 8290.

Almost surely, 2^31013440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31013440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39104316).

31013440 is an abundant number, since it is smaller than the sum of its proper divisors (47195192).

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

31013440 is a wasteful number, since it uses less digits than its factorization.

31013440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5735 (or 5725 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 31013440 is about 5568.9711796704. The cubic root of 31013440 is about 314.1834566971.

Adding to 31013440 its reverse (4431013), we get a palindrome (35444453).

The spelling of 31013440 in words is "thirty-one million, thirteen thousand, four hundred forty".