197633921 has 2 divisors, whose sum is σ = 197633922. Its totient is φ = 197633920.

The previous prime is 197633903. The next prime is 197633923. The reversal of 197633921 is 129336791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 194993296 + 2640625 = 13964^2 + 1625^2 .

It is a cyclic number.

It is not a de Polignac number, because 197633921 - 2¹⁸ = 197371777 is a prime.

Together with 197633923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (197633923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98816960 + 98816961.

It is an arithmetic number, because the mean of its divisors is an integer number (98816961).

Almost surely, 2^197633921 is an apocalyptic number.

It is an amenable number.

197633921 is a deficient number, since it is larger than the sum of its proper divisors (1).

197633921 is an equidigital number, since it uses as much as digits as its factorization.

197633921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 61236, while the sum is 41.

The square root of 197633921 is about 14058.2332104714. The cubic root of 197633921 is about 582.4882408428.

The spelling of 197633921 in words is "one hundred ninety-seven million, six hundred thirty-three thousand, nine hundred twenty-one".