197931857 has 4 divisors (see below), whose sum is σ = 199242816. Its totient is φ = 196620900.

The previous prime is 197931841. The next prime is 197931871. The reversal of 197931857 is 758139791.

197931857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 197931857 - 2⁴ = 197931841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (197931827) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 655253 + ... + 655554.

It is an arithmetic number, because the mean of its divisors is an integer number (49810704).

Almost surely, 2^197931857 is an apocalyptic number.

It is an amenable number.

197931857 is a deficient number, since it is larger than the sum of its proper divisors (1310959).

197931857 is a wasteful number, since it uses less digits than its factorization.

197931857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1310958.

The product of its digits is 476280, while the sum is 50.

The square root of 197931857 is about 14068.8257150339. The cubic root of 197931857 is about 582.7807970359.

The spelling of 197931857 in words is "one hundred ninety-seven million, nine hundred thirty-one thousand, eight hundred fifty-seven".