21224580 has 48 divisors (see below), whose sum is σ = 64002624. Its totient is φ = 5224320.

The previous prime is 21224579. The next prime is 21224591. The reversal of 21224580 is 8542212.

It is a self number, because there is not a number n which added to its sum of digits gives 21224580.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12826 + ... + 14385.

It is an arithmetic number, because the mean of its divisors is an integer number (1333388).

Almost surely, 2^21224580 is an apocalyptic number.

21224580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21224580 is an abundant number, since it is smaller than the sum of its proper divisors (42778044).

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

21224580 is a wasteful number, since it uses less digits than its factorization.

21224580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27236 (or 27234 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 21224580 is about 4607.0142174732. The cubic root of 21224580 is about 276.8724231901.

Adding to 21224580 its reverse (8542212), we get a palindrome (29766792).

The spelling of 21224580 in words is "twenty-one million, two hundred twenty-four thousand, five hundred eighty".