21841966 has 4 divisors (see below), whose sum is σ = 32762952. Its totient is φ = 10920982.

The previous prime is 21841913. The next prime is 21842021. The reversal of 21841966 is 66914812.

It is a happy number.

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

It is a congruent 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 as a sum of consecutive naturals, namely, 5460490 + ... + 5460493.

It is an arithmetic number, because the mean of its divisors is an integer number (8190738).

Almost surely, 2^21841966 is an apocalyptic number.

21841966 is a deficient number, since it is larger than the sum of its proper divisors (10920986).

21841966 is a wasteful number, since it uses less digits than its factorization.

21841966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10920985.

The product of its digits is 20736, while the sum is 37.

The square root of 21841966 is about 4673.5389160678. The cubic root of 21841966 is about 279.5313845175.

The spelling of 21841966 in words is "twenty-one million, eight hundred forty-one thousand, nine hundred sixty-six".