21089066 has 4 divisors (see below), whose sum is σ = 31633602. Its totient is φ = 10544532.

The previous prime is 21089051. The next prime is 21089087. The reversal of 21089066 is 66098012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18671041 + 2418025 = 4321^2 + 1555^2 .

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 as a sum of consecutive naturals, namely, 5272265 + ... + 5272268.

Almost surely, 2^21089066 is an apocalyptic number.

21089066 is a deficient number, since it is larger than the sum of its proper divisors (10544536).

21089066 is a wasteful number, since it uses less digits than its factorization.

21089066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10544535.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 21089066 is about 4592.2833100757. The cubic root of 21089066 is about 276.2819093243.

The spelling of 21089066 in words is "twenty-one million, eighty-nine thousand, sixty-six".