21222211021997 has 2 divisors, whose sum is σ = 21222211021998. Its totient is φ = 21222211021996.

The previous prime is 21222211021909. The next prime is 21222211022087. The reversal of 21222211021997 is 79912011222212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20108533936516 + 1113677085481 = 4484254^2 + 1055309^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222211021997 - 2⁸ = 21222211021741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21222211021597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611105510998 + 10611105510999.

It is an arithmetic number, because the mean of its divisors is an integer number (10611105510999).

Almost surely, 2^{21222211021997} is an apocalyptic number.

It is an amenable number.

21222211021997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222211021997 is an equidigital number, since it uses as much as digits as its factorization.

21222211021997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 41.

The spelling of 21222211021997 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred eleven million, twenty-one thousand, nine hundred ninety-seven".