21943166 has 16 divisors (see below), whose sum is σ = 38327904. Its totient is φ = 9226464.

The previous prime is 21943099. The next prime is 21943171. The reversal of 21943166 is 66134912.

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, 14045 + ... + 15528.

It is an arithmetic number, because the mean of its divisors is an integer number (2395494).

Almost surely, 2^21943166 is an apocalyptic number.

21943166 is a deficient number, since it is larger than the sum of its proper divisors (16384738).

21943166 is a wasteful number, since it uses less digits than its factorization.

21943166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29635.

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

The square root of 21943166 is about 4684.3533171613. The cubic root of 21943166 is about 279.9624354368.

The spelling of 21943166 in words is "twenty-one million, nine hundred forty-three thousand, one hundred sixty-six".