31221310232213 has 4 divisors (see below), whose sum is σ = 32864537086560. Its totient is φ = 29578083377868.

The previous prime is 31221310232209. The next prime is 31221310232221. The reversal of 31221310232213 is 31223201312213.

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 31221310232213 - 2² = 31221310232209 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31221310232243) 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, 821613427145 + ... + 821613427182.

It is an arithmetic number, because the mean of its divisors is an integer number (8216134271640).

Almost surely, 2^{31221310232213} is an apocalyptic number.

It is an amenable number.

31221310232213 is a deficient number, since it is larger than the sum of its proper divisors (1643226854347).

31221310232213 is a wasteful number, since it uses less digits than its factorization.

31221310232213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1643226854346.

The product of its (nonzero) digits is 2592, while the sum is 26.

Adding to 31221310232213 its reverse (31223201312213), we get a palindrome (62444511544426).

The spelling of 31221310232213 in words is "thirty-one trillion, two hundred twenty-one billion, three hundred ten million, two hundred thirty-two thousand, two hundred thirteen".