21089166 has 32 divisors (see below), whose sum is σ = 48584448. Its totient is φ = 5977920.

The previous prime is 21089161. The next prime is 21089171. The reversal of 21089166 is 66198012.

It is an interprime number because it is at equal distance from previous prime (21089161) and next prime (21089171).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21089161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3586 + ... + 7418.

It is an arithmetic number, because the mean of its divisors is an integer number (1518264).

Almost surely, 2^21089166 is an apocalyptic number.

21089166 is an abundant number, since it is smaller than the sum of its proper divisors (27495282).

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

21089166 is a wasteful number, since it uses less digits than its factorization.

21089166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3976.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 21089166 is about 4592.2941978928. The cubic root of 21089166 is about 276.2823460142.

The spelling of 21089166 in words is "twenty-one million, eighty-nine thousand, one hundred sixty-six".