21424866 has 8 divisors (see below), whose sum is σ = 42849744. Its totient is φ = 7141620.

The previous prime is 21424861. The next prime is 21424877. The reversal of 21424866 is 66842412.

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

21424866 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21424861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1785400 + ... + 1785411.

It is an arithmetic number, because the mean of its divisors is an integer number (5356218).

Almost surely, 2^21424866 is an apocalyptic number.

21424866 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.

21424866 is a wasteful number, since it uses less digits than its factorization.

21424866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3570816.

The product of its digits is 18432, while the sum is 33.

The square root of 21424866 is about 4628.7002495301. The cubic root of 21424866 is about 277.7406013299.

The spelling of 21424866 in words is "twenty-one million, four hundred twenty-four thousand, eight hundred sixty-six".