21782032 has 40 divisors (see below), whose sum is σ = 45338616. Its totient is φ = 10100736.

The previous prime is 21782017. The next prime is 21782039. The reversal of 21782032 is 23028712.

It can be written as a sum of positive squares in 4 ways, for example, as 4343056 + 17438976 = 2084^2 + 4176^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21781988 and 21782006.

It is not an unprimeable number, because it can be changed into a prime (21782039) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19308 + ... + 20404.

Almost surely, 2^21782032 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 21782032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22669308).

21782032 is an abundant number, since it is smaller than the sum of its proper divisors (23556584).

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

21782032 is a wasteful number, since it uses less digits than its factorization.

21782032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1195 (or 1189 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21782032 is about 4667.1224539324. The cubic root of 21782032 is about 279.2754737764.

The spelling of 21782032 in words is "twenty-one million, seven hundred eighty-two thousand, thirty-two".