21703247 has 2 divisors, whose sum is σ = 21703248. Its totient is φ = 21703246.

The previous prime is 21703229. The next prime is 21703277. The reversal of 21703247 is 74230712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21703247 - 2¹⁸ = 21441103 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21703277) 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, 10851623 + 10851624.

It is an arithmetic number, because the mean of its divisors is an integer number (10851624).

Almost surely, 2^21703247 is an apocalyptic number.

21703247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21703247 is an equidigital number, since it uses as much as digits as its factorization.

21703247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2352, while the sum is 26.

The square root of 21703247 is about 4658.6743822680. The cubic root of 21703247 is about 278.9383564775.

Adding to 21703247 its reverse (74230712), we get a palindrome (95933959).

The spelling of 21703247 in words is "twenty-one million, seven hundred three thousand, two hundred forty-seven".