21766080 has 224 divisors, whose sum is σ = 81930240. Its totient is φ = 4792320.

The previous prime is 21766079. The next prime is 21766097. The reversal of 21766080 is 8066712.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 275481 + ... + 275559.

It is an arithmetic number, because the mean of its divisors is an integer number (365760).

Almost surely, 2^21766080 is an apocalyptic number.

21766080 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 21766080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40965120).

21766080 is an abundant number, since it is smaller than the sum of its proper divisors (60164160).

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

21766080 is a wasteful number, since it uses less digits than its factorization.

21766080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147 (or 137 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 21766080 is about 4665.4131649834. The cubic root of 21766080 is about 279.2072816332.

It can be divided in two parts, 2176 and 6080, that added together give a triangular number (8256 = T₁₂₈).

The spelling of 21766080 in words is "twenty-one million, seven hundred sixty-six thousand, eighty".