21079393 has 2 divisors, whose sum is σ = 21079394. Its totient is φ = 21079392.

The previous prime is 21079391. The next prime is 21079459. The reversal of 21079393 is 39397012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13417569 + 7661824 = 3663^2 + 2768^2 .

It is a cyclic number.

It is not a de Polignac number, because 21079393 - 2¹ = 21079391 is a prime.

It is a super-3 number, since 3×21079393³ (a number of 23 digits) contains 333 as substring.

Together with 21079391, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21079391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10539696 + 10539697.

It is an arithmetic number, because the mean of its divisors is an integer number (10539697).

Almost surely, 2^21079393 is an apocalyptic number.

It is an amenable number.

21079393 is a deficient number, since it is larger than the sum of its proper divisors (1).

21079393 is an equidigital number, since it uses as much as digits as its factorization.

21079393 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10206, while the sum is 34.

The square root of 21079393 is about 4591.2300094855. The cubic root of 21079393 is about 276.2396617822.

The spelling of 21079393 in words is "twenty-one million, seventy-nine thousand, three hundred ninety-three".