21133979 has 2 divisors, whose sum is σ = 21133980. Its totient is φ = 21133978.

The previous prime is 21133967. The next prime is 21134021. The reversal of 21133979 is 97933112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21133979 - 2²⁴ = 4356763 is a prime.

It is not a weakly prime, because it can be changed into another prime (21133939) 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, 10566989 + 10566990.

It is an arithmetic number, because the mean of its divisors is an integer number (10566990).

Almost surely, 2^21133979 is an apocalyptic number.

21133979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21133979 is an equidigital number, since it uses as much as digits as its factorization.

21133979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10206, while the sum is 35.

The square root of 21133979 is about 4597.1707603699. The cubic root of 21133979 is about 276.4779011078.

The spelling of 21133979 in words is "twenty-one million, one hundred thirty-three thousand, nine hundred seventy-nine".