31321340 has 24 divisors (see below), whose sum is σ = 66361680. Its totient is φ = 12416768.

The previous prime is 31321321. The next prime is 31321349. The reversal of 31321340 is 4312313.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31321349) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4670 + ... + 9189.

It is an arithmetic number, because the mean of its divisors is an integer number (2765070).

Almost surely, 2^31321340 is an apocalyptic number.

It is an amenable number.

31321340 is an abundant number, since it is smaller than the sum of its proper divisors (35040340).

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

31321340 is a wasteful number, since it uses less digits than its factorization.

31321340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13981 (or 13979 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 31321340 is about 5596.5471498059. The cubic root of 31321340 is about 315.2197676927.

Adding to 31321340 its reverse (4312313), we get a palindrome (35633653).

The spelling of 31321340 in words is "thirty-one million, three hundred twenty-one thousand, three hundred forty".