21052230 has 16 divisors (see below), whose sum is σ = 50525424. Its totient is φ = 5613920.

The previous prime is 21052219. The next prime is 21052243. The reversal of 21052230 is 3225012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 350841 + ... + 350900.

It is an arithmetic number, because the mean of its divisors is an integer number (3157839).

Almost surely, 2^21052230 is an apocalyptic number.

21052230 is an abundant number, since it is smaller than the sum of its proper divisors (29473194).

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

21052230 is a wasteful number, since it uses less digits than its factorization.

21052230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701751.

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 21052230 is about 4588.2709161513. The cubic root of 21052230 is about 276.1209562253.

Adding to 21052230 its reverse (3225012), we get a palindrome (24277242).

The spelling of 21052230 in words is "twenty-one million, fifty-two thousand, two hundred thirty".