221112021421 has 2 divisors, whose sum is σ = 221112021422. Its totient is φ = 221112021420.

The previous prime is 221112021391. The next prime is 221112021439. The reversal of 221112021421 is 124120211122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144681336900 + 76430684521 = 380370^2 + 276461^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221112021421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221112021451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110556010710 + 110556010711.

It is an arithmetic number, because the mean of its divisors is an integer number (110556010711).

Almost surely, 2^221112021421 is an apocalyptic number.

It is an amenable number.

221112021421 is a deficient number, since it is larger than the sum of its proper divisors (1).

221112021421 is an equidigital number, since it uses as much as digits as its factorization.

221112021421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 221112021421 its reverse (124120211122), we get a palindrome (345232232543).

The spelling of 221112021421 in words is "two hundred twenty-one billion, one hundred twelve million, twenty-one thousand, four hundred twenty-one".