21353713 has 4 divisors (see below), whose sum is σ = 21464548. Its totient is φ = 21242880.

The previous prime is 21353711. The next prime is 21353737. The reversal of 21353713 is 31735312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7306209 + 14047504 = 2703^2 + 3748^2 .

It is a cyclic number.

It is not a de Polignac number, because 21353713 - 2¹ = 21353711 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21353711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55128 + ... + 55513.

It is an arithmetic number, because the mean of its divisors is an integer number (5366137).

Almost surely, 2^21353713 is an apocalyptic number.

It is an amenable number.

21353713 is a deficient number, since it is larger than the sum of its proper divisors (110835).

21353713 is a wasteful number, since it uses less digits than its factorization.

21353713 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110834.

The product of its digits is 1890, while the sum is 25.

The square root of 21353713 is about 4621.0077905150. The cubic root of 21353713 is about 277.4327970805.

The spelling of 21353713 in words is "twenty-one million, three hundred fifty-three thousand, seven hundred thirteen".