221212133231 has 4 divisors (see below), whose sum is σ = 221478976200. Its totient is φ = 220945290264.

The previous prime is 221212133189. The next prime is 221212133239. The reversal of 221212133231 is 132331212122.

221212133231 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221212133231 is a prime.

It is a super-2 number, since 2×221212133231² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221212133197 and 221212133206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221212133239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133420241 + ... + 133421898.

It is an arithmetic number, because the mean of its divisors is an integer number (55369744050).

Almost surely, 2^221212133231 is an apocalyptic number.

221212133231 is a deficient number, since it is larger than the sum of its proper divisors (266842969).

221212133231 is an equidigital number, since it uses as much as digits as its factorization.

221212133231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266842968.

The product of its digits is 864, while the sum is 23.

Adding to 221212133231 its reverse (132331212122), we get a palindrome (353543345353).

The spelling of 221212133231 in words is "two hundred twenty-one billion, two hundred twelve million, one hundred thirty-three thousand, two hundred thirty-one".