197072221 has 2 divisors, whose sum is σ = 197072222. Its totient is φ = 197072220.

The previous prime is 197072219. The next prime is 197072231. The reversal of 197072221 is 122270791.

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., 187306596 + 9765625 = 13686^2 + 3125^2 .

It is an emirp because it is prime and its reverse (122270791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 197072221 - 2¹ = 197072219 is a prime.

Together with 197072219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197072231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98536110 + 98536111.

It is an arithmetic number, because the mean of its divisors is an integer number (98536111).

Almost surely, 2^197072221 is an apocalyptic number.

It is an amenable number.

197072221 is a deficient number, since it is larger than the sum of its proper divisors (1).

197072221 is an equidigital number, since it uses as much as digits as its factorization.

197072221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3528, while the sum is 31.

The square root of 197072221 is about 14038.2413784633. The cubic root of 197072221 is about 581.9358827270.

The spelling of 197072221 in words is "one hundred ninety-seven million, seventy-two thousand, two hundred twenty-one".