21731703 has 16 divisors (see below), whose sum is σ = 33246720. Its totient is φ = 12368736.

The previous prime is 21731683. The next prime is 21731737. The reversal of 21731703 is 30713712.

It is not a de Polignac number, because 21731703 - 2⁸ = 21731447 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21751703) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3726 + ... + 7572.

It is an arithmetic number, because the mean of its divisors is an integer number (2077920).

Almost surely, 2^21731703 is an apocalyptic number.

21731703 is a deficient number, since it is larger than the sum of its proper divisors (11515017).

21731703 is a wasteful number, since it uses less digits than its factorization.

21731703 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4126.

The product of its (nonzero) digits is 882, while the sum is 24.

The square root of 21731703 is about 4661.7274695117. The cubic root of 21731703 is about 279.0602123355.

Subtracting 21731703 from its reverse (30713712), we obtain a square (8982009 = 2997²).

The spelling of 21731703 in words is "twenty-one million, seven hundred thirty-one thousand, seven hundred three".