21866672 has 10 divisors (see below), whose sum is σ = 42366708. Its totient is φ = 10933328.

The previous prime is 21866671. The next prime is 21866693. The reversal of 21866672 is 27666812.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21866671) 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 as a sum of consecutive naturals, namely, 683318 + ... + 683349.

Almost surely, 2^21866672 is an apocalyptic number.

It is an amenable number.

21866672 is a deficient number, since it is larger than the sum of its proper divisors (20500036).

21866672 is a wasteful number, since it uses less digits than its factorization.

21866672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1366675 (or 1366669 counting only the distinct ones).

The product of its digits is 48384, while the sum is 38.

The square root of 21866672 is about 4676.1813480660. The cubic root of 21866672 is about 279.6367398097.

The spelling of 21866672 in words is "twenty-one million, eight hundred sixty-six thousand, six hundred seventy-two".