21563080 has 64 divisors (see below), whose sum is σ = 60497280. Its totient is φ = 6720000.

The previous prime is 21563077. The next prime is 21563093. The reversal of 21563080 is 8036512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 421 + ... + 6580.

It is an arithmetic number, because the mean of its divisors is an integer number (945270).

Almost surely, 2^21563080 is an apocalyptic number.

21563080 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 21563080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30248640).

21563080 is an abundant number, since it is smaller than the sum of its proper divisors (38934200).

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

21563080 is a wasteful number, since it uses less digits than its factorization.

21563080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7030 (or 7026 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21563080 is about 4643.6063571324. The cubic root of 21563080 is about 278.3365659522.

Adding to 21563080 its reverse (8036512), we get a palindrome (29599592).

The spelling of 21563080 in words is "twenty-one million, five hundred sixty-three thousand, eighty".