21230712 has 48 divisors (see below), whose sum is σ = 57915000. Its totient is φ = 7025856.

The previous prime is 21230707. The next prime is 21230719. The reversal of 21230712 is 21703212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21230719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9739 + ... + 11717.

Almost surely, 2^21230712 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21230712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28957500).

21230712 is an abundant number, since it is smaller than the sum of its proper divisors (36684288).

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

21230712 is a wasteful number, since it uses less digits than its factorization.

21230712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2140 (or 2133 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21230712 is about 4607.6796763664. The cubic root of 21230712 is about 276.8990843886.

Adding to 21230712 its reverse (21703212), we get a palindrome (42933924).

The spelling of 21230712 in words is "twenty-one million, two hundred thirty thousand, seven hundred twelve".