31144640 has 28 divisors (see below), whose sum is σ = 74163936. Its totient is φ = 12457728.

The previous prime is 31144613. The next prime is 31144643. The reversal of 31144640 is 4644113.

It is not an unprimeable number, because it can be changed into a prime (31144643) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 48344 + ... + 48983.

It is an arithmetic number, because the mean of its divisors is an integer number (2648712).

Almost surely, 2^31144640 is an apocalyptic number.

It is an amenable number.

31144640 is an abundant number, since it is smaller than the sum of its proper divisors (43019296).

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

31144640 is an equidigital number, since it uses as much as digits as its factorization.

31144640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97344 (or 97334 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 31144640 is about 5580.7383024112. The cubic root of 31144640 is about 314.6258764835.

Adding to 31144640 its reverse (4644113), we get a palindrome (35788753).

The spelling of 31144640 in words is "thirty-one million, one hundred forty-four thousand, six hundred forty".