31304140 has 72 divisors (see below), whose sum is σ = 81012960. Its totient is φ = 10096128.

The previous prime is 31304107. The next prime is 31304159. The reversal of 31304140 is 4140313.

It is a super-2 number, since 2×31304140² = 1959898362279200, which contains 22 as substring.

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, 15721 + ... + 17599.

It is an arithmetic number, because the mean of its divisors is an integer number (1125180).

Almost surely, 2^31304140 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 31304140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40506480).

31304140 is an abundant number, since it is smaller than the sum of its proper divisors (49708820).

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

31304140 is a wasteful number, since it uses less digits than its factorization.

31304140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1919 (or 1910 counting only the distinct ones).

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

The square root of 31304140 is about 5595.0102770236. The cubic root of 31304140 is about 315.1620565310.

Adding to 31304140 its reverse (4140313), we get a palindrome (35444453).

The spelling of 31304140 in words is "thirty-one million, three hundred four thousand, one hundred forty".