31212123212221 has 16 divisors (see below), whose sum is σ = 37557688476160. Its totient is φ = 25338925796400.

The previous prime is 31212123212213. The next prime is 31212123212227. The reversal of 31212123212221 is 12221232121213.

It is a cyclic number.

It is not a de Polignac number, because 31212123212221 - 2³ = 31212123212213 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 (31212123212227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28426611 + ... + 29504176.

It is an arithmetic number, because the mean of its divisors is an integer number (2347355529760).

Almost surely, 2^{31212123212221} is an apocalyptic number.

It is an amenable number.

31212123212221 is a deficient number, since it is larger than the sum of its proper divisors (6345565263939).

31212123212221 is a wasteful number, since it uses less digits than its factorization.

31212123212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57934864.

The product of its digits is 1152, while the sum is 25.

Adding to 31212123212221 its reverse (12221232121213), we get a palindrome (43433355333434).

The spelling of 31212123212221 in words is "thirty-one trillion, two hundred twelve billion, one hundred twenty-three million, two hundred twelve thousand, two hundred twenty-one".