21546816 has 28 divisors (see below), whose sum is σ = 57009792. Its totient is φ = 7182208.

The previous prime is 21546787. The next prime is 21546823. The reversal of 21546816 is 61864512.

It is a congruent 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, 55920 + ... + 56303.

It is an arithmetic number, because the mean of its divisors is an integer number (2036064).

Almost surely, 2^21546816 is an apocalyptic number.

It is an amenable number.

21546816 is an abundant number, since it is smaller than the sum of its proper divisors (35462976).

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

21546816 is a wasteful number, since it uses less digits than its factorization.

21546816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112238 (or 112228 counting only the distinct ones).

The product of its digits is 11520, while the sum is 33.

The square root of 21546816 is about 4641.8548016930. The cubic root of 21546816 is about 278.2665696975.

The spelling of 21546816 in words is "twenty-one million, five hundred forty-six thousand, eight hundred sixteen".