21443942 has 16 divisors (see below), whose sum is σ = 35578032. Its totient is φ = 9629280.

The previous prime is 21443941. The next prime is 21443999. The reversal of 21443942 is 24934412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21443941) 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 7 ways as a sum of consecutive naturals, for example, 10184 + ... + 12107.

It is an arithmetic number, because the mean of its divisors is an integer number (2223627).

Almost surely, 2^21443942 is an apocalyptic number.

21443942 is a deficient number, since it is larger than the sum of its proper divisors (14134090).

21443942 is a wasteful number, since it uses less digits than its factorization.

21443942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22343.

The product of its digits is 6912, while the sum is 29.

The square root of 21443942 is about 4630.7604127184. The cubic root of 21443942 is about 277.8230072602.

The spelling of 21443942 in words is "twenty-one million, four hundred forty-three thousand, nine hundred forty-two".