21021846 has 16 divisors (see below), whose sum is σ = 43180464. Its totient is φ = 6817824.

The previous prime is 21021827. The next prime is 21021851. The reversal of 21021846 is 64812012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47125 + ... + 47568.

It is an arithmetic number, because the mean of its divisors is an integer number (2698779).

Almost surely, 2^21021846 is an apocalyptic number.

21021846 is an abundant number, since it is smaller than the sum of its proper divisors (22158618).

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

21021846 is a wasteful number, since it uses less digits than its factorization.

21021846 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94735.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 21021846 is about 4584.9586693884. The cubic root of 21021846 is about 275.9880534632.

Adding to 21021846 its reverse (64812012), we get a palindrome (85833858).

The spelling of 21021846 in words is "twenty-one million, twenty-one thousand, eight hundred forty-six".