21713449 has 8 divisors (see below), whose sum is σ = 22727232. Its totient is φ = 20705520.

The previous prime is 21713443. The next prime is 21713473. The reversal of 21713449 is 94431712.

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

It is a de Polignac number, because none of the positive numbers 2^k-21713449 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 21713449.

It is not an unprimeable number, because it can be changed into a prime (21713443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7314 + ... + 9844.

It is an arithmetic number, because the mean of its divisors is an integer number (2840904).

Almost surely, 2^21713449 is an apocalyptic number.

It is an amenable number.

21713449 is a deficient number, since it is larger than the sum of its proper divisors (1013783).

21713449 is a wasteful number, since it uses less digits than its factorization.

21713449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2927.

The product of its digits is 6048, while the sum is 31.

The square root of 21713449 is about 4659.7692002931. The cubic root of 21713449 is about 278.9820562879.

The spelling of 21713449 in words is "twenty-one million, seven hundred thirteen thousand, four hundred forty-nine".