21628896 has 96 divisors (see below), whose sum is σ = 62324640. Its totient is φ = 6537216.

The previous prime is 21628891. The next prime is 21628907. The reversal of 21628896 is 69882612.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21628891) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47100 + ... + 47556.

It is an arithmetic number, because the mean of its divisors is an integer number (649215).

Almost surely, 2^21628896 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 21628896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31162320).

21628896 is an abundant number, since it is smaller than the sum of its proper divisors (40695744).

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

21628896 is a wasteful number, since it uses less digits than its factorization.

21628896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516 (or 508 counting only the distinct ones).

The product of its digits is 82944, while the sum is 42.

The square root of 21628896 is about 4650.6876910840. The cubic root of 21628896 is about 278.6194629670.

The spelling of 21628896 in words is "twenty-one million, six hundred twenty-eight thousand, eight hundred ninety-six".