197212861 has 2 divisors, whose sum is σ = 197212862. Its totient is φ = 197212860.

The previous prime is 197212859. The next prime is 197212871. The reversal of 197212861 is 168212791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 192932100 + 4280761 = 13890^2 + 2069^2 .

It is a cyclic number.

It is not a de Polignac number, because 197212861 - 2¹ = 197212859 is a prime.

Together with 197212859, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 197212861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197212871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98606430 + 98606431.

It is an arithmetic number, because the mean of its divisors is an integer number (98606431).

Almost surely, 2^197212861 is an apocalyptic number.

It is an amenable number.

197212861 is a deficient number, since it is larger than the sum of its proper divisors (1).

197212861 is an equidigital number, since it uses as much as digits as its factorization.

197212861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 37.

The square root of 197212861 is about 14043.2496595339. The cubic root of 197212861 is about 582.0742820757.

The spelling of 197212861 in words is "one hundred ninety-seven million, two hundred twelve thousand, eight hundred sixty-one".