21750880 has 48 divisors (see below), whose sum is σ = 52179120. Its totient is φ = 8566272.

The previous prime is 21750863. The next prime is 21750887. The reversal of 21750880 is 8805712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21750887) 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 7 ways as a sum of consecutive naturals, for example, 9706 + ... + 11734.

It is an arithmetic number, because the mean of its divisors is an integer number (1087065).

Almost surely, 2^21750880 is an apocalyptic number.

21750880 is a gapful number since it is divisible by the number (20) 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 21750880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26089560).

21750880 is an abundant number, since it is smaller than the sum of its proper divisors (30428240).

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

21750880 is a wasteful number, since it uses less digits than its factorization.

21750880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2111 (or 2103 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 31.

The square root of 21750880 is about 4663.7838714932. The cubic root of 21750880 is about 279.1422731588.

The spelling of 21750880 in words is "twenty-one million, seven hundred fifty thousand, eight hundred eighty".