21166364 has 12 divisors (see below), whose sum is σ = 37308600. Its totient is φ = 10506768.

The previous prime is 21166357. The next prime is 21166367. The reversal of 21166364 is 46366112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21166367) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18479 + ... + 19590.

It is an arithmetic number, because the mean of its divisors is an integer number (3109050).

Almost surely, 2^21166364 is an apocalyptic number.

It is an amenable number.

21166364 is a deficient number, since it is larger than the sum of its proper divisors (16142236).

21166364 is a wasteful number, since it uses less digits than its factorization.

21166364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38212 (or 38210 counting only the distinct ones).

The product of its digits is 5184, while the sum is 29.

The square root of 21166364 is about 4600.6916871271. The cubic root of 21166364 is about 276.6190508530.

The spelling of 21166364 in words is "twenty-one million, one hundred sixty-six thousand, three hundred sixty-four".