21948666 has 16 divisors (see below), whose sum is σ = 46479744. Its totient is φ = 6885824.

The previous prime is 21948637. The next prime is 21948673. The reversal of 21948666 is 66684912.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107490 + ... + 107693.

It is an arithmetic number, because the mean of its divisors is an integer number (2904984).

Almost surely, 2^21948666 is an apocalyptic number.

21948666 is an abundant number, since it is smaller than the sum of its proper divisors (24531078).

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

21948666 is a wasteful number, since it uses less digits than its factorization.

21948666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215205.

The product of its digits is 124416, while the sum is 42.

The square root of 21948666 is about 4684.9403411356. The cubic root of 21948666 is about 279.9858241122.

The spelling of 21948666 in words is "twenty-one million, nine hundred forty-eight thousand, six hundred sixty-six".