21206966 has 16 divisors (see below), whose sum is σ = 36211968. Its totient is φ = 9220200.

The previous prime is 21206953. The next prime is 21206971. The reversal of 21206966 is 66960212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20450 + ... + 21461.

It is an arithmetic number, because the mean of its divisors is an integer number (2263248).

Almost surely, 2^21206966 is an apocalyptic number.

21206966 is a deficient number, since it is larger than the sum of its proper divisors (15005002).

21206966 is a wasteful number, since it uses less digits than its factorization.

21206966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41947.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21206966 is about 4605.1021704192. The cubic root of 21206966 is about 276.7958110646.

The spelling of 21206966 in words is "twenty-one million, two hundred six thousand, nine hundred sixty-six".