31261040 has 20 divisors (see below), whose sum is σ = 72682104. Its totient is φ = 12504384.

The previous prime is 31261039. The next prime is 31261067. The reversal of 31261040 is 4016213.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 195302 + ... + 195461.

Almost surely, 2^31261040 is an apocalyptic number.

It is an amenable number.

31261040 is an abundant number, since it is smaller than the sum of its proper divisors (41421064).

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

31261040 is a wasteful number, since it uses less digits than its factorization.

31261040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390776 (or 390770 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 31261040 is about 5591.1573041724. The cubic root of 31261040 is about 315.0173501823.

Adding to 31261040 its reverse (4016213), we get a palindrome (35277253).

The spelling of 31261040 in words is "thirty-one million, two hundred sixty-one thousand, forty".