31440013 has 4 divisors (see below), whose sum is σ = 34298208. Its totient is φ = 28581820.

The previous prime is 31440001. The next prime is 31440049. The reversal of 31440013 is 31004413.

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 not a de Polignac number, because 31440013 - 2⁹ = 31439501 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 (31440083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1429081 + ... + 1429102.

It is an arithmetic number, because the mean of its divisors is an integer number (8574552).

Almost surely, 2^31440013 is an apocalyptic number.

It is an amenable number.

31440013 is a deficient number, since it is larger than the sum of its proper divisors (2858195).

31440013 is a wasteful number, since it uses less digits than its factorization.

31440013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2858194.

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

The square root of 31440013 is about 5607.1394667870. The cubic root of 31440013 is about 315.6173765829.

Adding to 31440013 its reverse (31004413), we get a palindrome (62444426).

Subtracting from 31440013 its reverse (31004413), we obtain a square (435600 = 660²).

It can be divided in two parts, 314400 and 13, that added together give a palindrome (314413).

The spelling of 31440013 in words is "thirty-one million, four hundred forty thousand, thirteen".