21252560 has 40 divisors (see below), whose sum is σ = 56472576. Its totient is φ = 7286400.

The previous prime is 21252551. The next prime is 21252571. The reversal of 21252560 is 6525212.

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

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, 18416 + ... + 19535.

Almost surely, 2^21252560 is an apocalyptic number.

21252560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21252560 is an abundant number, since it is smaller than the sum of its proper divisors (35220016).

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

21252560 is a wasteful number, since it uses less digits than its factorization.

21252560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37971 (or 37965 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 21252560 is about 4610.0498912702. The cubic root of 21252560 is about 276.9940351559.

Adding to 21252560 its reverse (6525212), we get a palindrome (27777772).

It can be divided in two parts, 21252 and 560, that added together give a palindrome (21812).

The spelling of 21252560 in words is "twenty-one million, two hundred fifty-two thousand, five hundred sixty".