21713447 has 8 divisors (see below), whose sum is σ = 26121600. Its totient is φ = 17631864.

The previous prime is 21713443. The next prime is 21713473. The reversal of 21713447 is 74431712.

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 21713447 - 2² = 21713443 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 (21713443) 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, 81497 + ... + 81762.

It is an arithmetic number, because the mean of its divisors is an integer number (3265200).

Almost surely, 2^21713447 is an apocalyptic number.

21713447 is a deficient number, since it is larger than the sum of its proper divisors (4408153).

21713447 is a wasteful number, since it uses less digits than its factorization.

21713447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163285.

The product of its digits is 4704, while the sum is 29.

The square root of 21713447 is about 4659.7689856902. The cubic root of 21713447 is about 278.9820477223.

The spelling of 21713447 in words is "twenty-one million, seven hundred thirteen thousand, four hundred forty-seven".