31221210100213 has 4 divisors (see below), whose sum is σ = 35681382971680. Its totient is φ = 26761037228748.

The previous prime is 31221210100187. The next prime is 31221210100219. The reversal of 31221210100213 is 31200101212213.

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 31221210100213 - 2¹⁷ = 31221209969141 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 (31221210100219) 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, 2230086435723 + ... + 2230086435736.

It is an arithmetic number, because the mean of its divisors is an integer number (8920345742920).

Almost surely, 2^{31221210100213} is an apocalyptic number.

It is an amenable number.

31221210100213 is a deficient number, since it is larger than the sum of its proper divisors (4460172871467).

31221210100213 is an equidigital number, since it uses as much as digits as its factorization.

31221210100213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4460172871466.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 31221210100213 its reverse (31200101212213), we get a palindrome (62421311312426).

The spelling of 31221210100213 in words is "thirty-one trillion, two hundred twenty-one billion, two hundred ten million, one hundred thousand, two hundred thirteen".