21151166 has 16 divisors (see below), whose sum is σ = 32339184. Its totient is φ = 10373184.

The previous prime is 21151159. The next prime is 21151171. The reversal of 21151166 is 66115112.

It is a Curzon number.

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, 40181 + ... + 40703.

It is an arithmetic number, because the mean of its divisors is an integer number (2021199).

Almost surely, 2^21151166 is an apocalyptic number.

21151166 is a deficient number, since it is larger than the sum of its proper divisors (11188018).

21151166 is a wasteful number, since it uses less digits than its factorization.

21151166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 875.

The product of its digits is 360, while the sum is 23.

The square root of 21151166 is about 4599.0396823685. The cubic root of 21151166 is about 276.5528284424.

Adding to 21151166 its reverse (66115112), we get a palindrome (87266278).

The spelling of 21151166 in words is "twenty-one million, one hundred fifty-one thousand, one hundred sixty-six".