31143140 has 48 divisors (see below), whose sum is σ = 76349952. Its totient is φ = 10448256.

The previous prime is 31143113. The next prime is 31143157. The reversal of 31143140 is 4134113.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4214 + ... + 8946.

It is an arithmetic number, because the mean of its divisors is an integer number (1590624).

Almost surely, 2^31143140 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 31143140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38174976).

31143140 is an abundant number, since it is smaller than the sum of its proper divisors (45206812).

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

31143140 is a wasteful number, since it uses less digits than its factorization.

31143140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4796 (or 4794 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 31143140 is about 5580.6039099725. The cubic root of 31143140 is about 314.6208253587.

Adding to 31143140 its reverse (4134113), we get a palindrome (35277253).

The spelling of 31143140 in words is "thirty-one million, one hundred forty-three thousand, one hundred forty".