21285703 has 2 divisors, whose sum is σ = 21285704. Its totient is φ = 21285702.

The previous prime is 21285679. The next prime is 21285709. The reversal of 21285703 is 30758212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21285703 - 2¹⁷ = 21154631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21285709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10642851 + 10642852.

It is an arithmetic number, because the mean of its divisors is an integer number (10642852).

Almost surely, 2^21285703 is an apocalyptic number.

21285703 is a deficient number, since it is larger than the sum of its proper divisors (1).

21285703 is an equidigital number, since it uses as much as digits as its factorization.

21285703 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 21285703 is about 4613.6431374782. The cubic root of 21285703 is about 277.1379495080.

The spelling of 21285703 in words is "twenty-one million, two hundred eighty-five thousand, seven hundred three".