197681 has 4 divisors (see below), whose sum is σ = 215664. Its totient is φ = 179700.

The previous prime is 197677. The next prime is 197683. The reversal of 197681 is 186791.

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, and also an emirpimes, since its reverse is a distinct semiprime: 186791 = 11 ⋅16981.

It is a cyclic number.

It is not a de Polignac number, because 197681 - 2² = 197677 is a prime.

It is a super-2 number, since 2×197681² = 78155555522, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (197683) 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, 8975 + ... + 8996.

It is an arithmetic number, because the mean of its divisors is an integer number (53916).

2¹⁹⁷⁶⁸¹ is an apocalyptic number.

197681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

197681 is a deficient number, since it is larger than the sum of its proper divisors (17983).

197681 is a wasteful number, since it uses less digits than its factorization.

197681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17982.

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

The square root of 197681 is about 444.6133151402. The cubic root of 197681 is about 58.2534489291.

It can be divided in two parts, 197 and 681, that added together give a palindrome (878).

The spelling of 197681 in words is "one hundred ninety-seven thousand, six hundred eighty-one".