21068339 has 2 divisors, whose sum is σ = 21068340. Its totient is φ = 21068338.

The previous prime is 21068317. The next prime is 21068357. The reversal of 21068339 is 93386012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21068339 - 2²⁰ = 20019763 is a prime.

It is not a weakly prime, because it can be changed into another prime (21068309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10534169 + 10534170.

It is an arithmetic number, because the mean of its divisors is an integer number (10534170).

Almost surely, 2^21068339 is an apocalyptic number.

21068339 is a deficient number, since it is larger than the sum of its proper divisors (1).

21068339 is an equidigital number, since it uses as much as digits as its factorization.

21068339 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21068339 is about 4590.0260347846. The cubic root of 21068339 is about 276.1913667936.

The spelling of 21068339 in words is "twenty-one million, sixty-eight thousand, three hundred thirty-nine".