21724703 has 24 divisors (see below), whose sum is σ = 29404704. Its totient is φ = 15618240.

The previous prime is 21724663. The next prime is 21724721. The reversal of 21724703 is 30742712.

It is not a de Polignac number, because 21724703 - 2¹⁴ = 21708319 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21724783) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10025 + ... + 11997.

It is an arithmetic number, because the mean of its divisors is an integer number (1225196).

Almost surely, 2^21724703 is an apocalyptic number.

21724703 is a deficient number, since it is larger than the sum of its proper divisors (7680001).

21724703 is a wasteful number, since it uses less digits than its factorization.

21724703 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2015 (or 2004 counting only the distinct ones).

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

The square root of 21724703 is about 4660.9766144018. The cubic root of 21724703 is about 279.0302464179.

Subtracting 21724703 from its reverse (30742712), we obtain a square (9018009 = 3003²).

The spelling of 21724703 in words is "twenty-one million, seven hundred twenty-four thousand, seven hundred three".