21627816 has 96 divisors (see below), whose sum is σ = 64268640. Its totient is φ = 6045312.

The previous prime is 21627811. The next prime is 21627817. The reversal of 21627816 is 61872612.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21627811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 62155 + ... + 62501.

It is an arithmetic number, because the mean of its divisors is an integer number (669465).

Almost surely, 2^21627816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21627816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32134320).

21627816 is an abundant number, since it is smaller than the sum of its proper divisors (42640824).

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

21627816 is a wasteful number, since it uses less digits than its factorization.

21627816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 423 (or 412 counting only the distinct ones).

The product of its digits is 8064, while the sum is 33.

The square root of 21627816 is about 4650.5715777741. The cubic root of 21627816 is about 278.6148254360.

The spelling of 21627816 in words is "twenty-one million, six hundred twenty-seven thousand, eight hundred sixteen".