21704315 has 12 divisors (see below), whose sum is σ = 26467056. Its totient is φ = 17086608.

The previous prime is 21704303. The next prime is 21704317. The reversal of 21704315 is 51340712.

It is not a de Polignac number, because 21704315 - 2⁴ = 21704299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21704317) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21962 + ... + 22928.

It is an arithmetic number, because the mean of its divisors is an integer number (2205588).

Almost surely, 2^21704315 is an apocalyptic number.

21704315 is a deficient number, since it is larger than the sum of its proper divisors (4762741).

21704315 is an frugal number, since it uses more digits than its factorization.

21704315 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106 (or 1039 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21704315 is about 4658.7890057396. The cubic root of 21704315 is about 278.9429318494.

The spelling of 21704315 in words is "twenty-one million, seven hundred four thousand, three hundred fifteen".