31220203213 has 4 divisors (see below), whose sum is σ = 31223487708. Its totient is φ = 31216918720.

The previous prime is 31220203193. The next prime is 31220203219. The reversal of 31220203213 is 31230202213.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4398607684 + 26821595529 = 66322^2 + 163773^2 .

It is a cyclic number.

It is not a de Polignac number, because 31220203213 - 2²⁹ = 30683332301 is a prime.

It is a super-2 number, since 2×31220203213² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31220203219) 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, 1627948 + ... + 1647013.

It is an arithmetic number, because the mean of its divisors is an integer number (7805871927).

Almost surely, 2^31220203213 is an apocalyptic number.

It is an amenable number.

31220203213 is a deficient number, since it is larger than the sum of its proper divisors (3284495).

31220203213 is an equidigital number, since it uses as much as digits as its factorization.

31220203213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3284494.

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 31220203213 its reverse (31230202213), we get a palindrome (62450405426).

The spelling of 31220203213 in words is "thirty-one billion, two hundred twenty million, two hundred three thousand, two hundred thirteen".