197664857 has 8 divisors (see below), whose sum is σ = 212991240. Its totient is φ = 182355840.

The previous prime is 197664823. The next prime is 197664869. The reversal of 197664857 is 758466791.

It can be written as a sum of positive squares in 4 ways, for example, as 234256 + 197430601 = 484^2 + 14051^2 .

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 197664857 - 2¹⁰ = 197663833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 197664799 and 197664808.

It is not an unprimeable number, because it can be changed into a prime (197664877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28619 + ... + 34847.

It is an arithmetic number, because the mean of its divisors is an integer number (26623905).

Almost surely, 2^197664857 is an apocalyptic number.

It is an amenable number.

197664857 is a deficient number, since it is larger than the sum of its proper divisors (15326383).

197664857 is a wasteful number, since it uses less digits than its factorization.

197664857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8683.

The product of its digits is 2540160, while the sum is 53.

The square root of 197664857 is about 14059.3334479270. Note that the first 3 decimals coincide. The cubic root of 197664857 is about 582.5186319079.

The spelling of 197664857 in words is "one hundred ninety-seven million, six hundred sixty-four thousand, eight hundred fifty-seven".