21716499 has 8 divisors (see below), whose sum is σ = 33091840. Its totient is φ = 12409416.

The previous prime is 21716489. The next prime is 21716503. The reversal of 21716499 is 99461712.

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

It is not a de Polignac number, because 21716499 - 2⁷ = 21716371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21716479) 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, 517039 + ... + 517080.

It is an arithmetic number, because the mean of its divisors is an integer number (4136480).

Almost surely, 2^21716499 is an apocalyptic number.

21716499 is a deficient number, since it is larger than the sum of its proper divisors (11375341).

21716499 is a wasteful number, since it uses less digits than its factorization.

21716499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1034129.

The product of its digits is 27216, while the sum is 39.

The square root of 21716499 is about 4660.0964582292. The cubic root of 21716499 is about 278.9951181685.

Adding to 21716499 its product of digits (27216), we get a triangular number (21743715 = T₆₅₉₄).

The spelling of 21716499 in words is "twenty-one million, seven hundred sixteen thousand, four hundred ninety-nine".