21920832 has 84 divisors (see below), whose sum is σ = 66172080. Its totient is φ = 6918912.

The previous prime is 21920831. The next prime is 21920869. The reversal of 21920832 is 23802912.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21920796 and 21920805.

It is not an unprimeable number, because it can be changed into a prime (21920831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9943 + ... + 11945.

Almost surely, 2^21920832 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 21920832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33086040).

21920832 is an abundant number, since it is smaller than the sum of its proper divisors (44251248).

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

21920832 is a wasteful number, since it uses less digits than its factorization.

21920832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2040 (or 2027 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21920832 is about 4681.9688166411. The cubic root of 21920832 is about 279.8674202267.

The spelling of 21920832 in words is "twenty-one million, nine hundred twenty thousand, eight hundred thirty-two".