21881832 has 96 divisors (see below), whose sum is σ = 66484800. Its totient is φ = 5972736.

The previous prime is 21881831. The next prime is 21881851. The reversal of 21881832 is 23818812.

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

It is a junction number, because it is equal to n+sod(n) for n = 21881793 and 21881802.

It is not an unprimeable number, because it can be changed into a prime (21881831) 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, 26644 + ... + 27452.

It is an arithmetic number, because the mean of its divisors is an integer number (692550).

Almost surely, 2^21881832 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 21881832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33242400).

21881832 is an abundant number, since it is smaller than the sum of its proper divisors (44602968).

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

21881832 is a wasteful number, since it uses less digits than its factorization.

21881832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855 (or 844 counting only the distinct ones).

The product of its digits is 6144, while the sum is 33.

The square root of 21881832 is about 4677.8020479708. The cubic root of 21881832 is about 279.7013482339.

The spelling of 21881832 in words is "twenty-one million, eight hundred eighty-one thousand, eight hundred thirty-two".