21183830 has 16 divisors (see below), whose sum is σ = 38525760. Its totient is φ = 8385792.

The previous prime is 21183829. The next prime is 21183857. The reversal of 21183830 is 3838112.

It is a self number, because there is not a number n which added to its sum of digits gives 21183830.

It is a congruent number.

It is an unprimeable number.

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, 9950 + ... + 11889.

It is an arithmetic number, because the mean of its divisors is an integer number (2407860).

Almost surely, 2^21183830 is an apocalyptic number.

21183830 is a deficient number, since it is larger than the sum of its proper divisors (17341930).

21183830 is a wasteful number, since it uses less digits than its factorization.

21183830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21943.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 21183830 is about 4602.5894885379. The cubic root of 21183830 is about 276.6951165079.

The spelling of 21183830 in words is "twenty-one million, one hundred eighty-three thousand, eight hundred thirty".