21786834 has 8 divisors (see below), whose sum is σ = 43573680. Its totient is φ = 7262276.

The previous prime is 21786823. The next prime is 21786841. The reversal of 21786834 is 43868712.

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

21786834 is an admirable number.

It is a super-2 number, since 2×21786834² = 949332271487112, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21786792 and 21786801.

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 3 ways as a sum of consecutive naturals, for example, 1815564 + ... + 1815575.

It is an arithmetic number, because the mean of its divisors is an integer number (5446710).

Almost surely, 2^21786834 is an apocalyptic number.

21786834 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21786834 is a wasteful number, since it uses less digits than its factorization.

21786834 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3631144.

The product of its digits is 64512, while the sum is 39.

The square root of 21786834 is about 4667.6368753364. The cubic root of 21786834 is about 279.2959950067.

The spelling of 21786834 in words is "twenty-one million, seven hundred eighty-six thousand, eight hundred thirty-four".