116821 has 4 divisors (see below), whose sum is σ = 117612. Its totient is φ = 116032.

The previous prime is 116819. The next prime is 116827. The reversal of 116821 is 128611.

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.

It can be written as a sum of positive squares in 2 ways, for example, as 98596 + 18225 = 314^2 + 135^2 .

It is a cyclic number.

It is not a de Polignac number, because 116821 - 2¹ = 116819 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 (116827) 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, 100 + ... + 493.

It is an arithmetic number, because the mean of its divisors is an integer number (29403).

2¹¹⁶⁸²¹ is an apocalyptic number.

It is an amenable number.

116821 is a deficient number, since it is larger than the sum of its proper divisors (791).

116821 is an equidigital number, since it uses as much as digits as its factorization.

116821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790.

The product of its digits is 96, while the sum is 19.

The square root of 116821 is about 341.7908717330. The cubic root of 116821 is about 48.8847771641.

The spelling of 116821 in words is "one hundred sixteen thousand, eight hundred twenty-one".