31320040 has 32 divisors (see below), whose sum is σ = 70852680. Its totient is φ = 12460032.

The previous prime is 31320011. The next prime is 31320041. The reversal of 31320040 is 4002313.

It can be written as a sum of positive squares in 4 ways, for example, as 21548164 + 9771876 = 4642^2 + 3126^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 31320040.

It is not an unprimeable number, because it can be changed into a prime (31320041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5692 + ... + 9748.

Almost surely, 2^31320040 is an apocalyptic number.

It is an amenable number.

31320040 is an abundant number, since it is smaller than the sum of its proper divisors (39532640).

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

31320040 is a wasteful number, since it uses less digits than its factorization.

31320040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4261 (or 4257 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 31320040 is about 5596.4310055606. The cubic root of 31320040 is about 315.2154065408.

Adding to 31320040 its reverse (4002313), we get a palindrome (35322353).

The spelling of 31320040 in words is "thirty-one million, three hundred twenty thousand, forty".