31220013313 has 4 divisors (see below), whose sum is σ = 31221233748. Its totient is φ = 31218792880.

The previous prime is 31220013289. The next prime is 31220013323. The reversal of 31220013313 is 31331002213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31331002213 = 7 ⋅4475857459.

It can be written as a sum of positive squares in 2 ways, for example, as 12416199184 + 18803814129 = 111428^2 + 137127^2 .

It is a cyclic number.

It is not a de Polignac number, because 31220013313 - 2⁵ = 31220013281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31220013323) 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, 571006 + ... + 623287.

It is an arithmetic number, because the mean of its divisors is an integer number (7805308437).

Almost surely, 2^31220013313 is an apocalyptic number.

It is an amenable number.

31220013313 is a deficient number, since it is larger than the sum of its proper divisors (1220435).

31220013313 is a wasteful number, since it uses less digits than its factorization.

31220013313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1220434.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 31220013313 its reverse (31331002213), we get a palindrome (62551015526).

The spelling of 31220013313 in words is "thirty-one billion, two hundred twenty million, thirteen thousand, three hundred thirteen".