221212120323231 has 64 divisors (see below), whose sum is σ = 332022866365440. Its totient is φ = 147361331469312.

The previous prime is 221212120323217. The next prime is 221212120323239. The reversal of 221212120323231 is 132323021212122.

221212120323231 is a `hidden beast` number, since 2 + 2 + 1 + 212 + 120 + 3 + 2 + 323 + 1 = 666.

It is not a de Polignac number, because 221212120323231 - 2¹⁸ = 221212120061087 is a prime.

It is a super-2 number, since 2×221212120323231² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 221212120323195 and 221212120323204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221212120323239) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 19416488671 + ... + 19416500063.

It is an arithmetic number, because the mean of its divisors is an integer number (5187857286960).

Almost surely, 2^{221212120323231} is an apocalyptic number.

221212120323231 is a deficient number, since it is larger than the sum of its proper divisors (110810746042209).

221212120323231 is an equidigital number, since it uses as much as digits as its factorization.

221212120323231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17464 (or 17446 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

Adding to 221212120323231 its reverse (132323021212122), we get a palindrome (353535141535353).

The spelling of 221212120323231 in words is "two hundred twenty-one trillion, two hundred twelve billion, one hundred twenty million, three hundred twenty-three thousand, two hundred thirty-one".