21766480 has 40 divisors (see below), whose sum is σ = 50958792. Its totient is φ = 8646144.

The previous prime is 21766439. The next prime is 21766513. The reversal of 21766480 is 8466712.

It can be written as a sum of positive squares in 4 ways, for example, as 753424 + 21013056 = 868^2 + 4584^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11694 + ... + 13426.

Almost surely, 2^21766480 is an apocalyptic number.

21766480 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 21766480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25479396).

21766480 is an abundant number, since it is smaller than the sum of its proper divisors (29192312).

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

21766480 is a wasteful number, since it uses less digits than its factorization.

21766480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1903 (or 1897 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 21766480 is about 4665.4560334441. The cubic root of 21766480 is about 279.2089919737.

The spelling of 21766480 in words is "twenty-one million, seven hundred sixty-six thousand, four hundred eighty".