21006834 has 8 divisors (see below), whose sum is σ = 42013680. Its totient is φ = 7002276.

The previous prime is 21006829. The next prime is 21006847. The reversal of 21006834 is 43860012.

It is a happy number.

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

21006834 is an admirable number.

It is a Curzon 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, 1750564 + ... + 1750575.

It is an arithmetic number, because the mean of its divisors is an integer number (5251710).

Almost surely, 2^21006834 is an apocalyptic number.

21006834 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.

21006834 is a wasteful number, since it uses less digits than its factorization.

21006834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3501144.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 21006834 is about 4583.3212848326. The cubic root of 21006834 is about 275.9223421507.

Adding to 21006834 its reverse (43860012), we get a palindrome (64866846).

The spelling of 21006834 in words is "twenty-one million, six thousand, eight hundred thirty-four".