221302400021 has 2 divisors, whose sum is σ = 221302400022. Its totient is φ = 221302400020.

The previous prime is 221302399987. The next prime is 221302400027. The reversal of 221302400021 is 120004203122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149062399396 + 72240000625 = 386086^2 + 268775^2 .

It is a cyclic number.

It is not a de Polignac number, because 221302400021 - 2²² = 221298205717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221302400027) 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, 110651200010 + 110651200011.

It is an arithmetic number, because the mean of its divisors is an integer number (110651200011).

Almost surely, 2^221302400021 is an apocalyptic number.

It is an amenable number.

221302400021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221302400021 is an equidigital number, since it uses as much as digits as its factorization.

221302400021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 221302400021 its reverse (120004203122), we get a palindrome (341306603143).

The spelling of 221302400021 in words is "two hundred twenty-one billion, three hundred two million, four hundred thousand, twenty-one".