21716746 has 16 divisors (see below), whose sum is σ = 33076224. Its totient is φ = 10692864.

The previous prime is 21716731. The next prime is 21716749. The reversal of 21716746 is 64761712.

It is a happy number.

21716746 is nontrivially palindromic in base 15.

It is not an unprimeable number, because it can be changed into a prime (21716749) 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 7 ways as a sum of consecutive naturals, for example, 48801 + ... + 49243.

It is an arithmetic number, because the mean of its divisors is an integer number (2067264).

Almost surely, 2^21716746 is an apocalyptic number.

21716746 is a deficient number, since it is larger than the sum of its proper divisors (11359478).

21716746 is a wasteful number, since it uses less digits than its factorization.

21716746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765.

The product of its digits is 14112, while the sum is 34.

The square root of 21716746 is about 4660.1229597512. The cubic root of 21716746 is about 278.9961759131.

The spelling of 21716746 in words is "twenty-one million, seven hundred sixteen thousand, seven hundred forty-six".