21083399 has 2 divisors, whose sum is σ = 21083400. Its totient is φ = 21083398.

The previous prime is 21083393. The next prime is 21083429. The reversal of 21083399 is 99338012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21083399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21083393) 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 as a sum of consecutive naturals, namely, 10541699 + 10541700.

It is an arithmetic number, because the mean of its divisors is an integer number (10541700).

Almost surely, 2^21083399 is an apocalyptic number.

21083399 is a deficient number, since it is larger than the sum of its proper divisors (1).

21083399 is an equidigital number, since it uses as much as digits as its factorization.

21083399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 21083399 is about 4591.6662552934. Note that the first 3 decimals coincide. The cubic root of 21083399 is about 276.2571598507.

The spelling of 21083399 in words is "twenty-one million, eighty-three thousand, three hundred ninety-nine".