31240140 has 48 divisors (see below), whose sum is σ = 87720192. Its totient is φ = 8307136.

The previous prime is 31240129. The next prime is 31240159. The reversal of 31240140 is 4104213.

It is a Harshad number since it is a multiple of its sum of digits (15).

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, 34777 + ... + 35663.

It is an arithmetic number, because the mean of its divisors is an integer number (1827504).

Almost surely, 2^31240140 is an apocalyptic number.

31240140 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31240140 is an abundant number, since it is smaller than the sum of its proper divisors (56480052).

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

31240140 is a wasteful number, since it uses less digits than its factorization.

31240140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1486 (or 1484 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 31240140 is about 5589.2879689635. The cubic root of 31240140 is about 314.9471314648.

Adding to 31240140 its reverse (4104213), we get a palindrome (35344353).

The spelling of 31240140 in words is "thirty-one million, two hundred forty thousand, one hundred forty".