21703213 has 8 divisors (see below), whose sum is σ = 24943680. Its totient is φ = 18497760.

The previous prime is 21703211. The next prime is 21703229. The reversal of 21703213 is 31230712.

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 21703213 - 2¹ = 21703211 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21703211) 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, 7408 + ... + 9913.

It is an arithmetic number, because the mean of its divisors is an integer number (3117960).

Almost surely, 2^21703213 is an apocalyptic number.

It is an amenable number.

21703213 is a deficient number, since it is larger than the sum of its proper divisors (3240467).

21703213 is a wasteful number, since it uses less digits than its factorization.

21703213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17507.

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

The square root of 21703213 is about 4658.6707331598. The cubic root of 21703213 is about 278.9382108171.

Adding to 21703213 its reverse (31230712), we get a palindrome (52933925).

The spelling of 21703213 in words is "twenty-one million, seven hundred three thousand, two hundred thirteen".