196821 has 12 divisors (see below), whose sum is σ = 299520. Its totient is φ = 124200.

The previous prime is 196817. The next prime is 196831. The reversal of 196821 is 128691.

It is not a de Polignac number, because 196821 - 2² = 196817 is a prime.

196821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (196831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 405 + ... + 746.

It is an arithmetic number, because the mean of its divisors is an integer number (24960).

2¹⁹⁶⁸²¹ is an apocalyptic number.

It is an amenable number.

196821 is a deficient number, since it is larger than the sum of its proper divisors (102699).

196821 is a wasteful number, since it uses less digits than its factorization.

196821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1176 (or 1173 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 196821 is about 443.6451284529. The cubic root of 196821 is about 58.1688500187.

It can be divided in two parts, 19682 and 1, that added together give a 9-th power (19683 = 3⁹).

The spelling of 196821 in words is "one hundred ninety-six thousand, eight hundred twenty-one".