197861 has 4 divisors (see below), whose sum is σ = 198924. Its totient is φ = 196800.

The previous prime is 197837. The next prime is 197887. The reversal of 197861 is 168791.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 168791 = 7 ⋅24113.

It can be written as a sum of positive squares in 2 ways, for example, as 101761 + 96100 = 319^2 + 310^2 .

It is a cyclic number.

It is not a de Polignac number, because 197861 - 2¹⁰ = 196837 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 (197831) 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, 170 + ... + 651.

It is an arithmetic number, because the mean of its divisors is an integer number (49731).

2¹⁹⁷⁸⁶¹ is an apocalyptic number.

It is an amenable number.

197861 is a deficient number, since it is larger than the sum of its proper divisors (1063).

197861 is an equidigital number, since it uses as much as digits as its factorization.

197861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1062.

The product of its digits is 3024, while the sum is 32.

The square root of 197861 is about 444.8156921692. The cubic root of 197861 is about 58.2711246117.

The spelling of 197861 in words is "one hundred ninety-seven thousand, eight hundred sixty-one".