979821 has 6 divisors (see below), whose sum is σ = 1415310. Its totient is φ = 653208.

The previous prime is 979819. The next prime is 979831. The reversal of 979821 is 128979.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 864900 + 114921 = 930^2 + 339^2 .

It is not a de Polignac number, because 979821 - 2¹ = 979819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (979831) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 54426 + ... + 54443.

It is an arithmetic number, because the mean of its divisors is an integer number (235885).

2⁹⁷⁹⁸²¹ is an apocalyptic number.

It is an amenable number.

979821 is a deficient number, since it is larger than the sum of its proper divisors (435489).

979821 is a wasteful number, since it uses less digits than its factorization.

979821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108875 (or 108872 counting only the distinct ones).

The product of its digits is 9072, while the sum is 36.

The square root of 979821 is about 989.8590808797. The cubic root of 979821 is about 99.3227908975.

The spelling of 979821 in words is "nine hundred seventy-nine thousand, eight hundred twenty-one".