197811 has 12 divisors (see below), whose sum is σ = 295360. Its totient is φ = 127440.

The previous prime is 197807. The next prime is 197831. The reversal of 197811 is 118791.

It is not a de Polignac number, because 197811 - 2² = 197807 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 197811.

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 11 ways as a sum of consecutive naturals, for example, 76 + ... + 633.

2¹⁹⁷⁸¹¹ is an apocalyptic number.

197811 is a deficient number, since it is larger than the sum of its proper divisors (97549).

197811 is a wasteful number, since it uses less digits than its factorization.

197811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 746 (or 743 counting only the distinct ones).

The product of its digits is 504, while the sum is 27.

The square root of 197811 is about 444.7594855650. The cubic root of 197811 is about 58.2662157756.

The spelling of 197811 in words is "one hundred ninety-seven thousand, eight hundred eleven".