31090140 has 72 divisors (see below), whose sum is σ = 95488848. Its totient is φ = 8186880.

The previous prime is 31090139. The next prime is 31090141. The reversal of 31090140 is 4109013.

It is an interprime number because it is at equal distance from previous prime (31090139) and next prime (31090141).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31090141) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13900 + ... + 15980.

It is an arithmetic number, because the mean of its divisors is an integer number (1326234).

Almost surely, 2^31090140 is an apocalyptic number.

31090140 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31090140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47744424).

31090140 is an abundant number, since it is smaller than the sum of its proper divisors (64398708).

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

31090140 is a wasteful number, since it uses less digits than its factorization.

31090140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2179 (or 2174 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 31090140 is about 5575.8532979267. The cubic root of 31090140 is about 314.4422480762.

Adding to 31090140 its reverse (4109013), we get a palindrome (35199153).

The spelling of 31090140 in words is "thirty-one million, ninety thousand, one hundred forty".