221888197 has 2 divisors, whose sum is σ = 221888198. Its totient is φ = 221888196.

The previous prime is 221888143. The next prime is 221888201. The reversal of 221888197 is 791888122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 122567041 + 99321156 = 11071^2 + 9966^2 .

It is a cyclic number.

It is not a de Polignac number, because 221888197 - 2²³ = 213499589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221889197) 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, 110944098 + 110944099.

It is an arithmetic number, because the mean of its divisors is an integer number (110944099).

Almost surely, 2^221888197 is an apocalyptic number.

It is an amenable number.

221888197 is a deficient number, since it is larger than the sum of its proper divisors (1).

221888197 is an equidigital number, since it uses as much as digits as its factorization.

221888197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129024, while the sum is 46.

The square root of 221888197 is about 14895.9120902347. The cubic root of 221888197 is about 605.4032300394.

The spelling of 221888197 in words is "two hundred twenty-one million, eight hundred eighty-eight thousand, one hundred ninety-seven".