21716911 has 8 divisors (see below), whose sum is σ = 22803120. Its totient is φ = 20653248.

The previous prime is 21716887. The next prime is 21716927. The reversal of 21716911 is 11961712.

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 21716911 - 2¹¹ = 21714863 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 21716911.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21716941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3646 + ... + 7531.

It is an arithmetic number, because the mean of its divisors is an integer number (2850390).

Almost surely, 2^21716911 is an apocalyptic number.

21716911 is a deficient number, since it is larger than the sum of its proper divisors (1086209).

21716911 is a wasteful number, since it uses less digits than its factorization.

21716911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11273.

The product of its digits is 756, while the sum is 28.

The square root of 21716911 is about 4660.1406631131. The cubic root of 21716911 is about 278.9968824992.

The spelling of 21716911 in words is "twenty-one million, seven hundred sixteen thousand, nine hundred eleven".