220221997 has 2 divisors, whose sum is σ = 220221998. Its totient is φ = 220221996.

The previous prime is 220221983. The next prime is 220222001. The reversal of 220221997 is 799122022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138156516 + 82065481 = 11754^2 + 9059^2 .

It is a cyclic number.

It is not a de Polignac number, because 220221997 - 2¹¹ = 220219949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220221977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110110998 + 110110999.

It is an arithmetic number, because the mean of its divisors is an integer number (110110999).

Almost surely, 2^220221997 is an apocalyptic number.

It is an amenable number.

220221997 is a deficient number, since it is larger than the sum of its proper divisors (1).

220221997 is an equidigital number, since it uses as much as digits as its factorization.

220221997 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 34.

The square root of 220221997 is about 14839.8786046248. The cubic root of 220221997 is about 603.8840590362.

It can be divided in two parts, 22022 and 1997, that multiplied together give a palindrome (43977934).

The spelling of 220221997 in words is "two hundred twenty million, two hundred twenty-one thousand, nine hundred ninety-seven".