21626808 has 128 divisors (see below), whose sum is σ = 67046400. Its totient is φ = 5677056.

The previous prime is 21626797. The next prime is 21626819. The reversal of 21626808 is 80862612.

It is an interprime number because it is at equal distance from previous prime (21626797) and next prime (21626819).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 111960 + ... + 112152.

It is an arithmetic number, because the mean of its divisors is an integer number (523800).

Almost surely, 2^21626808 is an apocalyptic number.

21626808 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21626808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33523200).

21626808 is an abundant number, since it is smaller than the sum of its proper divisors (45419592).

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

21626808 is a wasteful number, since it uses less digits than its factorization.

21626808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261 (or 257 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 21626808 is about 4650.4632027358. The cubic root of 21626808 is about 278.6104969344.

The spelling of 21626808 in words is "twenty-one million, six hundred twenty-six thousand, eight hundred eight".