21632688 has 120 divisors (see below), whose sum is σ = 75518976. Its totient is φ = 5616000.

The previous prime is 21632671. The next prime is 21632717. The reversal of 21632688 is 88623612.

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10113 + ... + 12063.

Almost surely, 2^21632688 is an apocalyptic number.

21632688 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 21632688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37759488).

21632688 is an abundant number, since it is smaller than the sum of its proper divisors (53886288).

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

21632688 is a wasteful number, since it uses less digits than its factorization.

21632688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1983 (or 1974 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 21632688 is about 4651.0953548600. The cubic root of 21632688 is about 278.6357446312.

It can be divided in two parts, 2163 and 2688, that added together give a triangular number (4851 = T₉₈).

The spelling of 21632688 in words is "twenty-one million, six hundred thirty-two thousand, six hundred eighty-eight".