197899857 has 12 divisors (see below), whose sum is σ = 295712820. Its totient is φ = 127383648.

The previous prime is 197899853. The next prime is 197899859. The reversal of 197899857 is 758998791.

It can be written as a sum of positive squares in 2 ways, for example, as 154853136 + 43046721 = 12444^2 + 6561^2 .

It is not a de Polignac number, because 197899857 - 2² = 197899853 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 197899794 and 197899803.

It is not an unprimeable number, because it can be changed into a prime (197899853) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 378858 + ... + 379379.

It is an arithmetic number, because the mean of its divisors is an integer number (24642735).

Almost surely, 2^197899857 is an apocalyptic number.

It is an amenable number.

197899857 is a deficient number, since it is larger than the sum of its proper divisors (97812963).

197899857 is a wasteful number, since it uses less digits than its factorization.

197899857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 758272 (or 758269 counting only the distinct ones).

The product of its digits is 11430720, while the sum is 63.

The square root of 197899857 is about 14067.6884028614. The cubic root of 197899857 is about 582.7493889360.

It can be divided in two parts, 1978998 and 57, that added together give a triangular number (1979055 = T₁₉₈₉).

The spelling of 197899857 in words is "one hundred ninety-seven million, eight hundred ninety-nine thousand, eight hundred fifty-seven".