21226752 has 144 divisors (see below), whose sum is σ = 65244480. Its totient is φ = 6801408.

The previous prime is 21226741. The next prime is 21226757. The reversal of 21226752 is 25762212.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21226757) 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, 255703 + ... + 255785.

Almost surely, 2^21226752 is an apocalyptic number.

21226752 is the 2304-th decagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21226752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32622240).

21226752 is an abundant number, since it is smaller than the sum of its proper divisors (44017728).

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

21226752 is an equidigital number, since it uses as much as digits as its factorization.

21226752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145 (or 125 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 21226752 is about 4607.2499389549. The cubic root of 21226752 is about 276.8818673721.

Adding to 21226752 its reverse (25762212), we get a palindrome (46988964).

The spelling of 21226752 in words is "twenty-one million, two hundred twenty-six thousand, seven hundred fifty-two".