21230610 has 64 divisors (see below), whose sum is σ = 55054080. Its totient is φ = 5223680.

The previous prime is 21230597. The next prime is 21230611. The reversal of 21230610 is 1603212.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21230610.

It is not an unprimeable number, because it can be changed into a prime (21230611) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 19480 + ... + 20540.

It is an arithmetic number, because the mean of its divisors is an integer number (860220).

Almost surely, 2^21230610 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21230610, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27527040).

21230610 is an abundant number, since it is smaller than the sum of its proper divisors (33823470).

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

21230610 is a wasteful number, since it uses less digits than its factorization.

21230610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1123.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 21230610 is about 4607.6686078754. The cubic root of 21230610 is about 276.8986409468.

Adding to 21230610 its reverse (1603212), we get a palindrome (22833822).

The spelling of 21230610 in words is "twenty-one million, two hundred thirty thousand, six hundred ten".