21704313 has 4 divisors (see below), whose sum is σ = 28939088. Its totient is φ = 14469540.

The previous prime is 21704303. The next prime is 21704317. The reversal of 21704313 is 31340712.

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.

It is not a de Polignac number, because 21704313 - 2¹³ = 21696121 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 21704313.

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 3 ways as a sum of consecutive naturals, for example, 3617383 + ... + 3617388.

It is an arithmetic number, because the mean of its divisors is an integer number (7234772).

Almost surely, 2^21704313 is an apocalyptic number.

It is an amenable number.

21704313 is a deficient number, since it is larger than the sum of its proper divisors (7234775).

21704313 is an equidigital number, since it uses as much as digits as its factorization.

21704313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7234774.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 21704313 is about 4658.7887910915. The cubic root of 21704313 is about 278.9429232814.

The spelling of 21704313 in words is "twenty-one million, seven hundred four thousand, three hundred thirteen".