197644861 has 8 divisors (see below), whose sum is σ = 203455800. Its totient is φ = 191858688.

The previous prime is 197644793. The next prime is 197644877. The reversal of 197644861 is 168446791.

It can be written as a sum of positive squares in 4 ways, for example, as 145660761 + 51984100 = 12069^2 + 7210^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 197644861 - 2¹¹ = 197642813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197641861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10665 + ... + 22561.

It is an arithmetic number, because the mean of its divisors is an integer number (25431975).

Almost surely, 2^197644861 is an apocalyptic number.

It is an amenable number.

197644861 is a deficient number, since it is larger than the sum of its proper divisors (5810939).

197644861 is a wasteful number, since it uses less digits than its factorization.

197644861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12383.

The product of its digits is 290304, while the sum is 46.

The square root of 197644861 is about 14058.6223009227. The cubic root of 197644861 is about 582.4989884981.

The spelling of 197644861 in words is "one hundred ninety-seven million, six hundred forty-four thousand, eight hundred sixty-one".