21184830 has 48 divisors (see below), whose sum is σ = 55311984. Its totient is φ = 5625600.

The previous prime is 21184747. The next prime is 21184859. The reversal of 21184830 is 3848112.

It is a junction number, because it is equal to n+sod(n) for n = 21184794 and 21184803.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 35797 + ... + 36383.

It is an arithmetic number, because the mean of its divisors is an integer number (1152333).

Almost surely, 2^21184830 is an apocalyptic number.

21184830 is an abundant number, since it is smaller than the sum of its proper divisors (34127154).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21184830 is a wasteful number, since it uses less digits than its factorization.

21184830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1001 (or 998 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 21184830 is about 4602.6981217542. The cubic root of 21184830 is about 276.6994703124.

The spelling of 21184830 in words is "twenty-one million, one hundred eighty-four thousand, eight hundred thirty".