197564399 has 2 divisors, whose sum is σ = 197564400. Its totient is φ = 197564398.

The previous prime is 197564371. The next prime is 197564401. The reversal of 197564399 is 993465791.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 197564399 - 2²⁴ = 180787183 is a prime.

Together with 197564401, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 197564399.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (197564309) 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, 98782199 + 98782200.

It is an arithmetic number, because the mean of its divisors is an integer number (98782200).

Almost surely, 2^197564399 is an apocalyptic number.

197564399 is a deficient number, since it is larger than the sum of its proper divisors (1).

197564399 is an equidigital number, since it uses as much as digits as its factorization.

197564399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1837080, while the sum is 53.

The square root of 197564399 is about 14055.7603494084. The cubic root of 197564399 is about 582.4199318929.

The spelling of 197564399 in words is "one hundred ninety-seven million, five hundred sixty-four thousand, three hundred ninety-nine".