21703841 has 4 divisors (see below), whose sum is σ = 21713712. Its totient is φ = 21693972.

The previous prime is 21703831. The next prime is 21703853. The reversal of 21703841 is 14830712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21703841 - 2¹⁸ = 21441697 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21703841.

It is not an unprimeable number, because it can be changed into a prime (21703831) 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 in 3 ways as a sum of consecutive naturals, for example, 26 + ... + 6588.

It is an arithmetic number, because the mean of its divisors is an integer number (5428428).

Almost surely, 2^21703841 is an apocalyptic number.

It is an amenable number.

21703841 is a deficient number, since it is larger than the sum of its proper divisors (9871).

21703841 is an equidigital number, since it uses as much as digits as its factorization.

21703841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9870.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 21703841 is about 4658.7381338727. The cubic root of 21703841 is about 278.9409012253.

The spelling of 21703841 in words is "twenty-one million, seven hundred three thousand, eight hundred forty-one".