31221220213 has 8 divisors (see below), whose sum is σ = 31406384736. Its totient is φ = 31036110000.

The previous prime is 31221220181. The next prime is 31221220237. The reversal of 31221220213 is 31202212213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31221220213 - 2⁵ = 31221220181 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 (31221220813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2112058 + ... + 2126788.

It is an arithmetic number, because the mean of its divisors is an integer number (3925798092).

Almost surely, 2^31221220213 is an apocalyptic number.

It is an amenable number.

31221220213 is a deficient number, since it is larger than the sum of its proper divisors (185164523).

31221220213 is a wasteful number, since it uses less digits than its factorization.

31221220213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27155.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 31221220213 its reverse (31202212213), we get a palindrome (62423432426).

The spelling of 31221220213 in words is "thirty-one billion, two hundred twenty-one million, two hundred twenty thousand, two hundred thirteen".