21966208 has 32 divisors (see below), whose sum is σ = 47742120. Its totient is φ = 9984000.

The previous prime is 21966181. The next prime is 21966209. The reversal of 21966208 is 80266912.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21966209) 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 3 ways as a sum of consecutive naturals, for example, 6393 + ... + 9208.

Almost surely, 2^21966208 is an apocalyptic number.

It is an amenable number.

21966208 is an abundant number, since it is smaller than the sum of its proper divisors (25775912).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21966208 is a wasteful number, since it uses less digits than its factorization.

21966208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15626 (or 15614 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 21966208 is about 4686.8121361966. The cubic root of 21966208 is about 280.0603951353.

The spelling of 21966208 in words is "twenty-one million, nine hundred sixty-six thousand, two hundred eight".