21766012 has 12 divisors (see below), whose sum is σ = 38369520. Its totient is φ = 10803296.

The previous prime is 21766007. The next prime is 21766033. The reversal of 21766012 is 21066712.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19312 + ... + 20407.

It is an arithmetic number, because the mean of its divisors is an integer number (3197460).

Almost surely, 2^21766012 is an apocalyptic number.

It is an amenable number.

21766012 is a deficient number, since it is larger than the sum of its proper divisors (16603508).

21766012 is a wasteful number, since it uses less digits than its factorization.

21766012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39860 (or 39858 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 21766012 is about 4665.4058773059. The cubic root of 21766012 is about 279.2069908732.

The spelling of 21766012 in words is "twenty-one million, seven hundred sixty-six thousand, twelve".