197885621 has 2 divisors, whose sum is σ = 197885622. Its totient is φ = 197885620.

The previous prime is 197885609. The next prime is 197885659. The reversal of 197885621 is 126588791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 197093521 + 792100 = 14039^2 + 890^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-197885621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197885021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98942810 + 98942811.

It is an arithmetic number, because the mean of its divisors is an integer number (98942811).

Almost surely, 2^197885621 is an apocalyptic number.

It is an amenable number.

197885621 is a deficient number, since it is larger than the sum of its proper divisors (1).

197885621 is an equidigital number, since it uses as much as digits as its factorization.

197885621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 47.

The square root of 197885621 is about 14067.1824115563. The cubic root of 197885621 is about 582.7354151694.

The spelling of 197885621 in words is "one hundred ninety-seven million, eight hundred eighty-five thousand, six hundred twenty-one".