31230640 has 120 divisors (see below), whose sum is σ = 87530112. Its totient is φ = 10321920.

The previous prime is 31230629. The next prime is 31230653. The reversal of 31230640 is 4603213.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 121392 + ... + 121648.

Almost surely, 2^31230640 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 31230640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43765056).

31230640 is an abundant number, since it is smaller than the sum of its proper divisors (56299472).

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

31230640 is a wasteful number, since it uses less digits than its factorization.

31230640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315 (or 302 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 31230640 is about 5588.4380644327. The cubic root of 31230640 is about 314.9152035127.

Adding to 31230640 its reverse (4603213), we get a palindrome (35833853).

The spelling of 31230640 in words is "thirty-one million, two hundred thirty thousand, six hundred forty".