31431040 has 64 divisors (see below), whose sum is σ = 76365360. Its totient is φ = 12367872.

The previous prime is 31431031. The next prime is 31431121. The reversal of 31431040 is 4013413.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 42514 + ... + 43246.

Almost surely, 2^31431040 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 31431040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38182680).

31431040 is an abundant number, since it is smaller than the sum of its proper divisors (44934320).

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

31431040 is an equidigital number, since it uses as much as digits as its factorization.

31431040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819 (or 807 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 31431040 is about 5606.3392690775. The cubic root of 31431040 is about 315.5873479250.

Adding to 31431040 its reverse (4013413), we get a palindrome (35444453).

The spelling of 31431040 in words is "thirty-one million, four hundred thirty-one thousand, forty".