979921 has 2 divisors, whose sum is σ = 979922. Its totient is φ = 979920.

The previous prime is 979919. The next prime is 979949. The reversal of 979921 is 129979.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 929296 + 50625 = 964^2 + 225^2 .

It is a cyclic number.

It is not a de Polignac number, because 979921 - 2¹ = 979919 is a prime.

Together with 979919, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (971921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 489960 + 489961.

It is an arithmetic number, because the mean of its divisors is an integer number (489961).

2⁹⁷⁹⁹²¹ is an apocalyptic number.

It is an amenable number.

979921 is a deficient number, since it is larger than the sum of its proper divisors (1).

979921 is an equidigital number, since it uses as much as digits as its factorization.

979921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10206, while the sum is 37.

The square root of 979921 is about 989.9095918315. The cubic root of 979921 is about 99.3261697260.

The spelling of 979921 in words is "nine hundred seventy-nine thousand, nine hundred twenty-one".