21080576 has 80 divisors (see below), whose sum is σ = 48612960. Its totient is φ = 9031680.

The previous prime is 21080573. The next prime is 21080599. The reversal of 21080576 is 67508012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21080573) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 106910 + ... + 107106.

It is an arithmetic number, because the mean of its divisors is an integer number (607662).

Almost surely, 2^21080576 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 21080576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24306480).

21080576 is an abundant number, since it is smaller than the sum of its proper divisors (27532384).

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

21080576 is a wasteful number, since it uses less digits than its factorization.

21080576 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245 (or 229 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 21080576 is about 4591.3588402563. The cubic root of 21080576 is about 276.2448293157.

Adding to 21080576 its reverse (67508012), we get a palindrome (88588588).

The spelling of 21080576 in words is "twenty-one million, eighty thousand, five hundred seventy-six".