21816266 has 8 divisors (see below), whose sum is σ = 32797380. Its totient is φ = 10883808.

The previous prime is 21816247. The next prime is 21816271. The reversal of 21816266 is 66261812.

It can be written as a sum of positive squares in 2 ways, for example, as 19175641 + 2640625 = 4379^2 + 1625^2 .

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

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 11021 + ... + 12848.

Almost surely, 2^21816266 is an apocalyptic number.

21816266 is a deficient number, since it is larger than the sum of its proper divisors (10981114).

21816266 is a wasteful number, since it uses less digits than its factorization.

21816266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24328.

The product of its digits is 6912, while the sum is 32.

The square root of 21816266 is about 4670.7885843827. The cubic root of 21816266 is about 279.4217061113.

The spelling of 21816266 in words is "twenty-one million, eight hundred sixteen thousand, two hundred sixty-six".