21302713 has 8 divisors (see below), whose sum is σ = 21978440. Its totient is φ = 20632320.

The previous prime is 21302707. The next prime is 21302731. The reversal of 21302713 is 31720312.

It can be written as a sum of positive squares in 4 ways, for example, as 6953769 + 14348944 = 2637^2 + 3788^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21302713 - 2⁵ = 21302681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21302753) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7723 + ... + 10111.

It is an arithmetic number, because the mean of its divisors is an integer number (2747305).

Almost surely, 2^21302713 is an apocalyptic number.

It is an amenable number.

21302713 is a deficient number, since it is larger than the sum of its proper divisors (675727).

21302713 is a wasteful number, since it uses less digits than its factorization.

21302713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2667.

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 21302713 is about 4615.4862149074. The cubic root of 21302713 is about 277.2117527450.

The spelling of 21302713 in words is "twenty-one million, three hundred two thousand, seven hundred thirteen".