21055066 has 8 divisors (see below), whose sum is σ = 31895604. Its totient is φ = 10423200.

The previous prime is 21055063. The next prime is 21055087. The reversal of 21055066 is 66055012.

It can be written as a sum of positive squares in 2 ways, for example, as 17464041 + 3591025 = 4179^2 + 1895^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21055066.

It is not an unprimeable number, because it can be changed into a prime (21055063) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51915 + ... + 52318.

Almost surely, 2^21055066 is an apocalyptic number.

21055066 is a deficient number, since it is larger than the sum of its proper divisors (10840538).

21055066 is a wasteful number, since it uses less digits than its factorization.

21055066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104336.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 21055066 is about 4588.5799546265. The cubic root of 21055066 is about 276.1333546564.

The spelling of 21055066 in words is "twenty-one million, fifty-five thousand, sixty-six".