21160866 has 16 divisors (see below), whose sum is σ = 42489504. Its totient is φ = 7025664.

The previous prime is 21160849. The next prime is 21160871. The reversal of 21160866 is 66806112.

It is an unprimeable number.

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, 5320 + ... + 8403.

It is an arithmetic number, because the mean of its divisors is an integer number (2655594).

Almost surely, 2^21160866 is an apocalyptic number.

21160866 is an abundant number, since it is smaller than the sum of its proper divisors (21328638).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21160866 is a wasteful number, since it uses less digits than its factorization.

21160866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13985.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 21160866 is about 4600.0941294717. The cubic root of 21160866 is about 276.5950980185.

Adding to 21160866 its reverse (66806112), we get a palindrome (87966978).

The spelling of 21160866 in words is "twenty-one million, one hundred sixty thousand, eight hundred sixty-six".