31285140 has 48 divisors (see below), whose sum is σ = 88022592. Its totient is φ = 8302336.

The previous prime is 31285139. The next prime is 31285157. The reversal of 31285140 is 4158213.

It is a self number, because there is not a number n which added to its sum of digits gives 31285140.

It is a congruent number.

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, 12472 + ... + 14768.

It is an arithmetic number, because the mean of its divisors is an integer number (1833804).

Almost surely, 2^31285140 is an apocalyptic number.

31285140 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31285140 is an abundant number, since it is smaller than the sum of its proper divisors (56737452).

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

31285140 is a wasteful number, since it uses less digits than its factorization.

31285140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2536 (or 2534 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 31285140 is about 5593.3120778301. The cubic root of 31285140 is about 315.0982812500.

The spelling of 31285140 in words is "thirty-one million, two hundred eighty-five thousand, one hundred forty".