21226560 has 56 divisors (see below), whose sum is σ = 67397376. Its totient is φ = 5660160.

The previous prime is 21226547. The next prime is 21226571. The reversal of 21226560 is 6562212.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21226560.

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, 10096 + ... + 12015.

Almost surely, 2^21226560 is an apocalyptic number.

21226560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21226560 is an abundant number, since it is smaller than the sum of its proper divisors (46170816).

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

21226560 is a wasteful number, since it uses less digits than its factorization.

21226560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22131 (or 22121 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 21226560 is about 4607.2291021828. The cubic root of 21226560 is about 276.8810325532.

Adding to 21226560 its reverse (6562212), we get a palindrome (27788772).

The spelling of 21226560 in words is "twenty-one million, two hundred twenty-six thousand, five hundred sixty".