21682838 has 8 divisors (see below), whose sum is σ = 34236120. Its totient is φ = 10270800.

The previous prime is 21682823. The next prime is 21682847. The reversal of 21682838 is 83828612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (38), and also a Moran number because the ratio is a prime number: 570601 = 21682838 / (2 + 1 + 6 + 8 + 2 + 8 + 3 + 8).

It is a Curzon number.

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 3 ways as a sum of consecutive naturals, for example, 285263 + ... + 285338.

It is an arithmetic number, because the mean of its divisors is an integer number (4279515).

Almost surely, 2^21682838 is an apocalyptic number.

21682838 is a deficient number, since it is larger than the sum of its proper divisors (12553282).

21682838 is a wasteful number, since it uses less digits than its factorization.

21682838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 570622.

The product of its digits is 36864, while the sum is 38.

The square root of 21682838 is about 4656.4834371014. The cubic root of 21682838 is about 278.8508943218.

The spelling of 21682838 in words is "twenty-one million, six hundred eighty-two thousand, eight hundred thirty-eight".