197959621 has 2 divisors, whose sum is σ = 197959622. Its totient is φ = 197959620.

The previous prime is 197959609. The next prime is 197959627. The reversal of 197959621 is 126959791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 104837121 + 93122500 = 10239^2 + 9650^2 .

It is a cyclic number.

It is not a de Polignac number, because 197959621 - 2⁵ = 197959589 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197959627) 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, 98979810 + 98979811.

It is an arithmetic number, because the mean of its divisors is an integer number (98979811).

Almost surely, 2^197959621 is an apocalyptic number.

It is an amenable number.

197959621 is a deficient number, since it is larger than the sum of its proper divisors (1).

197959621 is an equidigital number, since it uses as much as digits as its factorization.

197959621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 306180, while the sum is 49.

The square root of 197959621 is about 14069.8124010237. The cubic root of 197959621 is about 582.8080447460.

The spelling of 197959621 in words is "one hundred ninety-seven million, nine hundred fifty-nine thousand, six hundred twenty-one".