21383816 has 16 divisors (see below), whose sum is σ = 42205200. Its totient is φ = 10129104.

The previous prime is 21383777. The next prime is 21383833. The reversal of 21383816 is 61838312.

It is a happy 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, 70190 + ... + 70493.

It is an arithmetic number, because the mean of its divisors is an integer number (2637825).

Almost surely, 2^21383816 is an apocalyptic number.

It is an amenable number.

21383816 is a deficient number, since it is larger than the sum of its proper divisors (20821384).

21383816 is a wasteful number, since it uses less digits than its factorization.

21383816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140708 (or 140704 counting only the distinct ones).

The product of its digits is 6912, while the sum is 32.

The square root of 21383816 is about 4624.2638333036. The cubic root of 21383816 is about 277.5631044432.

The spelling of 21383816 in words is "twenty-one million, three hundred eighty-three thousand, eight hundred sixteen".