197128643 has 4 divisors (see below), whose sum is σ = 197163120. Its totient is φ = 197094168.

The previous prime is 197128627. The next prime is 197128663. The reversal of 197128643 is 346821791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 197128643 - 2⁴ = 197128627 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 197128643.

It is not an unprimeable number, because it can be changed into a prime (197128663) 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 in 3 ways as a sum of consecutive naturals, for example, 6383 + ... + 20856.

It is an arithmetic number, because the mean of its divisors is an integer number (49290780).

Almost surely, 2^197128643 is an apocalyptic number.

197128643 is a deficient number, since it is larger than the sum of its proper divisors (34477).

197128643 is an equidigital number, since it uses as much as digits as its factorization.

197128643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34476.

The product of its digits is 72576, while the sum is 41.

The square root of 197128643 is about 14040.2508168480. The cubic root of 197128643 is about 581.9914137285.

The spelling of 197128643 in words is "one hundred ninety-seven million, one hundred twenty-eight thousand, six hundred forty-three".