21269760 has 144 divisors (see below), whose sum is σ = 70640640. Its totient is φ = 5447680.

The previous prime is 21269747. The next prime is 21269777. The reversal of 21269760 is 6796212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111265 + ... + 111455.

It is an arithmetic number, because the mean of its divisors is an integer number (490560).

Almost surely, 2^21269760 is an apocalyptic number.

21269760 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 21269760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35320320).

21269760 is an abundant number, since it is smaller than the sum of its proper divisors (49370880).

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

21269760 is a wasteful number, since it uses less digits than its factorization.

21269760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 21269760 is about 4611.9150035533. The cubic root of 21269760 is about 277.0687400810.

The spelling of 21269760 in words is "twenty-one million, two hundred sixty-nine thousand, seven hundred sixty".