197908857 has 6 divisors (see below), whose sum is σ = 285868362. Its totient is φ = 131939232.

The previous prime is 197908853. The next prime is 197908897. The reversal of 197908857 is 758809791.

It can be written as a sum of positive squares in only one way, i.e., 197711721 + 197136 = 14061^2 + 444^2 .

It is not a de Polignac number, because 197908857 - 2² = 197908853 is a prime.

It is not an unprimeable number, because it can be changed into a prime (197908853) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10994928 + ... + 10994945.

It is an arithmetic number, because the mean of its divisors is an integer number (47644727).

Almost surely, 2^197908857 is an apocalyptic number.

It is an amenable number.

197908857 is a deficient number, since it is larger than the sum of its proper divisors (87959505).

197908857 is a wasteful number, since it uses less digits than its factorization.

197908857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21989879 (or 21989876 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 54.

The square root of 197908857 is about 14068.0082812031. The cubic root of 197908857 is about 582.7582228063.

It can be divided in two parts, 197908 and 857, that added together give a triangular number (198765 = T₆₃₀).

The spelling of 197908857 in words is "one hundred ninety-seven million, nine hundred eight thousand, eight hundred fifty-seven".