221220221231 has 2 divisors, whose sum is σ = 221220221232. Its totient is φ = 221220221230.

The previous prime is 221220221171. The next prime is 221220221269. The reversal of 221220221231 is 132122022122.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221220221231 is a prime.

It is a super-2 number, since 2×221220221231² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221220221291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110610110615 + 110610110616.

It is an arithmetic number, because the mean of its divisors is an integer number (110610110616).

Almost surely, 2^221220221231 is an apocalyptic number.

221220221231 is a deficient number, since it is larger than the sum of its proper divisors (1).

221220221231 is an equidigital number, since it uses as much as digits as its factorization.

221220221231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 221220221231 its reverse (132122022122), we get a palindrome (353342243353).

The spelling of 221220221231 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred twenty-one thousand, two hundred thirty-one".