21067166 has 16 divisors (see below), whose sum is σ = 33747840. Its totient is φ = 9841440.

The previous prime is 21067159. The next prime is 21067177. The reversal of 21067166 is 66176012.

It is a super-3 number, since 3×21067166³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4061 + ... + 7656.

It is an arithmetic number, because the mean of its divisors is an integer number (2109240).

Almost surely, 2^21067166 is an apocalyptic number.

21067166 is a deficient number, since it is larger than the sum of its proper divisors (12680674).

21067166 is a wasteful number, since it uses less digits than its factorization.

21067166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11779.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 21067166 is about 4589.8982559530. The cubic root of 21067166 is about 276.1862409586.

It can be divided in two parts, 210 and 67166, that added together give a palindrome (67376).

The spelling of 21067166 in words is "twenty-one million, sixty-seven thousand, one hundred sixty-six".