22001221997 has 2 divisors, whose sum is σ = 22001221998. Its totient is φ = 22001221996.

The previous prime is 22001221943. The next prime is 22001222003. The reversal of 22001221997 is 79912210022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13751314756 + 8249907241 = 117266^2 + 90829^2 .

It is a cyclic number.

It is not a de Polignac number, because 22001221997 - 2²⁰ = 22000173421 is a prime.

It is a super-2 number, since 2×22001221997² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22001229997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11000610998 + 11000610999.

It is an arithmetic number, because the mean of its divisors is an integer number (11000610999).

Almost surely, 2^22001221997 is an apocalyptic number.

It is an amenable number.

22001221997 is a deficient number, since it is larger than the sum of its proper divisors (1).

22001221997 is an equidigital number, since it uses as much as digits as its factorization.

22001221997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 35.

The spelling of 22001221997 in words is "twenty-two billion, one million, two hundred twenty-one thousand, nine hundred ninety-seven".