21433220 has 12 divisors (see below), whose sum is σ = 45009804.
Its totient is φ = 8573280.
The previous prime is 21433219. The next prime is 21433231. The reversal of 21433220 is 2233412.
It can be written as a sum of positive squares in 2 ways, for example, as 3319684 + 18113536 = 1822^2 + 4256^2
It is an unprimeable number.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 535811 + ... + 535850.
It is an arithmetic number, because the mean of its divisors is an integer number (3750817).
Almost surely, 221433220 is an apocalyptic number.
21433220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.
It is an amenable number.
21433220 is an abundant number, since it is smaller than the sum of its proper divisors (23576584).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
21433220 is a wasteful number, since it uses less digits than its factorization.
21433220 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1071670 (or 1071668 counting only the distinct ones).
The product of its (nonzero) digits is 288, while the sum is 17.
The square root of 21433220 is about 4629.6025747358.
The cubic root of 21433220 is about 277.7766955810.
Adding to 21433220 its reverse (2233412), we get a palindrome (23666632).
The spelling of 21433220 in words is "twenty-one million, four hundred thirty-three thousand, two hundred twenty".