21842646 has 16 divisors (see below), whose sum is σ = 49926144. Its totient is φ = 6240744.

The previous prime is 21842593. The next prime is 21842651. The reversal of 21842646 is 64624812.

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 7 ways as a sum of consecutive naturals, for example, 259990 + ... + 260073.

It is an arithmetic number, because the mean of its divisors is an integer number (3120384).

Almost surely, 2^21842646 is an apocalyptic number.

21842646 is an abundant number, since it is smaller than the sum of its proper divisors (28083498).

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

21842646 is a wasteful number, since it uses less digits than its factorization.

21842646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520075.

The product of its digits is 18432, while the sum is 33.

The square root of 21842646 is about 4673.6116655109. The cubic root of 21842646 is about 279.5342853456.

The spelling of 21842646 in words is "twenty-one million, eight hundred forty-two thousand, six hundred forty-six".