21048666 has 8 divisors (see below), whose sum is σ = 42097344. Its totient is φ = 7016220.

The previous prime is 21048649. The next prime is 21048701. The reversal of 21048666 is 66684012.

It is a happy number.

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

21048666 is an admirable number.

It is a Curzon number.

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 3 ways as a sum of consecutive naturals, for example, 1754050 + ... + 1754061.

It is an arithmetic number, because the mean of its divisors is an integer number (5262168).

Almost surely, 2^21048666 is an apocalyptic number.

21048666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21048666 is a wasteful number, since it uses less digits than its factorization.

21048666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3508116.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 21048666 is about 4587.8825181123. The cubic root of 21048666 is about 276.1053735431.

The spelling of 21048666 in words is "twenty-one million, forty-eight thousand, six hundred sixty-six".