31212121312221 has 32 divisors (see below), whose sum is σ = 47982763670400. Its totient is φ = 17913565071360.

The previous prime is 31212121312219. The next prime is 31212121312223. The reversal of 31212121312221 is 12221312121213.

It is an interprime number because it is at equal distance from previous prime (31212121312219) and next prime (31212121312223).

It is not a de Polignac number, because 31212121312221 - 2¹ = 31212121312219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31212121312191 and 31212121312200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31212121312223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 555327960 + ... + 555384161.

It is an arithmetic number, because the mean of its divisors is an integer number (1499461364700).

Almost surely, 2^{31212121312221} is an apocalyptic number.

It is an amenable number.

31212121312221 is a deficient number, since it is larger than the sum of its proper divisors (16770642358179).

31212121312221 is a wasteful number, since it uses less digits than its factorization.

31212121312221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1110712189.

The product of its digits is 576, while the sum is 24.

Adding to 31212121312221 its reverse (12221312121213), we get a palindrome (43433433433434).

The spelling of 31212121312221 in words is "thirty-one trillion, two hundred twelve billion, one hundred twenty-one million, three hundred twelve thousand, two hundred twenty-one".