21224260 has 48 divisors (see below), whose sum is σ = 46335744. Its totient is φ = 8160768.

The previous prime is 21224249. The next prime is 21224267. The reversal of 21224260 is 6242212.

It is not an unprimeable number, because it can be changed into a prime (21224267) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62812 + ... + 63148.

It is an arithmetic number, because the mean of its divisors is an integer number (965328).

Almost surely, 2^21224260 is an apocalyptic number.

21224260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21224260 is an abundant number, since it is smaller than the sum of its proper divisors (25111484).

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

21224260 is a wasteful number, since it uses less digits than its factorization.

21224260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460 (or 458 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21224260 is about 4606.9794876904. The cubic root of 21224260 is about 276.8710317276.

Adding to 21224260 its reverse (6242212), we get a palindrome (27466472).

The spelling of 21224260 in words is "twenty-one million, two hundred twenty-four thousand, two hundred sixty".