31240440013 has 4 divisors (see below), whose sum is σ = 31465191520. Its totient is φ = 31015688508.

The previous prime is 31240439911. The next prime is 31240440019. The reversal of 31240440013 is 31004404213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31240440013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31240440019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112375545 + ... + 112375822.

It is an arithmetic number, because the mean of its divisors is an integer number (7866297880).

Almost surely, 2^31240440013 is an apocalyptic number.

It is an amenable number.

31240440013 is a deficient number, since it is larger than the sum of its proper divisors (224751507).

31240440013 is a wasteful number, since it uses less digits than its factorization.

31240440013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224751506.

The product of its (nonzero) digits is 1152, while the sum is 22.

Adding to 31240440013 its reverse (31004404213), we get a palindrome (62244844226).

The spelling of 31240440013 in words is "thirty-one billion, two hundred forty million, four hundred forty thousand, thirteen".