21264448 has 28 divisors (see below), whose sum is σ = 42999660. Its totient is φ = 10429952.

The previous prime is 21264427. The next prime is 21264449. The reversal of 21264448 is 84446212.

It can be written as a sum of positive squares in 2 ways, for example, as 11075584 + 10188864 = 3328^2 + 3192^2 .

It is not an unprimeable number, because it can be changed into a prime (21264449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 258 + ... + 6526.

Almost surely, 2^21264448 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 21264448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21499830).

21264448 is an abundant number, since it is smaller than the sum of its proper divisors (21735212).

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

21264448 is an equidigital number, since it uses as much as digits as its factorization.

21264448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6334 (or 6324 counting only the distinct ones).

The product of its digits is 12288, while the sum is 31.

The square root of 21264448 is about 4611.3390679932. The cubic root of 21264448 is about 277.0456727202.

It can be divided in two parts, 21264 and 448, that added together give a palindrome (21712).

The spelling of 21264448 in words is "twenty-one million, two hundred sixty-four thousand, four hundred forty-eight".