21442808 has 16 divisors (see below), whose sum is σ = 41953680. Its totient is φ = 10255168.

The previous prime is 21442777. The next prime is 21442819. The reversal of 21442808 is 80824412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58085 + ... + 58452.

It is an arithmetic number, because the mean of its divisors is an integer number (2622105).

Almost surely, 2^21442808 is an apocalyptic number.

It is an amenable number.

21442808 is a deficient number, since it is larger than the sum of its proper divisors (20510872).

21442808 is a wasteful number, since it uses less digits than its factorization.

21442808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116566 (or 116562 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 29.

The square root of 21442808 is about 4630.6379690060. The cubic root of 21442808 is about 277.8181098889.

The spelling of 21442808 in words is "twenty-one million, four hundred forty-two thousand, eight hundred eight".