921979 has 4 divisors (see below), whose sum is σ = 924984. Its totient is φ = 918976.

The previous prime is 921959. The next prime is 921989. The reversal of 921979 is 979129.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 979129 = 709 ⋅1381.

It is a cyclic number.

It is not a de Polignac number, because 921979 - 2⁹ = 921467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 982 + ... + 1675.

It is an arithmetic number, because the mean of its divisors is an integer number (231246).

2⁹²¹⁹⁷⁹ is an apocalyptic number.

921979 is a deficient number, since it is larger than the sum of its proper divisors (3005).

921979 is a wasteful number, since it uses less digits than its factorization.

921979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3004.

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

The square root of 921979 is about 960.1973755432. The cubic root of 921979 is about 97.3285701157.

The spelling of 921979 in words is "nine hundred twenty-one thousand, nine hundred seventy-nine".