21267166 has 16 divisors (see below), whose sum is σ = 32509440. Its totient is φ = 10432800.

The previous prime is 21267161. The next prime is 21267227. The reversal of 21267166 is 66176212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21267161) 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 in 7 ways as a sum of consecutive naturals, for example, 25240 + ... + 26068.

It is an arithmetic number, because the mean of its divisors is an integer number (2031840).

Almost surely, 2^21267166 is an apocalyptic number.

21267166 is a deficient number, since it is larger than the sum of its proper divisors (11242274).

21267166 is a wasteful number, since it uses less digits than its factorization.

21267166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1059.

The product of its digits is 6048, while the sum is 31.

The square root of 21267166 is about 4611.6337668987. The cubic root of 21267166 is about 277.0574761155.

The spelling of 21267166 in words is "twenty-one million, two hundred sixty-seven thousand, one hundred sixty-six".