31864140 has 288 divisors, whose sum is σ = 127895040. Its totient is φ = 6272640.

The previous prime is 31864139. The next prime is 31864153. The reversal of 31864140 is 4146813.

31864140 is a `hidden beast` number, since 3 + 18 + 641 + 4 + 0 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1677051 + ... + 1677069.

It is an arithmetic number, because the mean of its divisors is an integer number (444080).

Almost surely, 2^31864140 is an apocalyptic number.

31864140 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 31864140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63947520).

31864140 is an abundant number, since it is smaller than the sum of its proper divisors (96030900).

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

31864140 is a wasteful number, since it uses less digits than its factorization.

31864140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 31864140 is about 5644.8330356176. The cubic root of 31864140 is about 317.0302723962.

The spelling of 31864140 in words is "thirty-one million, eight hundred sixty-four thousand, one hundred forty".