21264248 has 16 divisors (see below), whose sum is σ = 39923280. Its totient is φ = 10618048.

The previous prime is 21264241. The next prime is 21264251. The reversal of 21264248 is 84246212.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 21264248.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21264241) 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 3 ways as a sum of consecutive naturals, for example, 7565 + ... + 9987.

It is an arithmetic number, because the mean of its divisors is an integer number (2495205).

Almost surely, 2^21264248 is an apocalyptic number.

It is an amenable number.

21264248 is a deficient number, since it is larger than the sum of its proper divisors (18659032).

21264248 is a wasteful number, since it uses less digits than its factorization.

21264248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3526 (or 3522 counting only the distinct ones).

The product of its digits is 6144, while the sum is 29.

The square root of 21264248 is about 4611.3173822672. The cubic root of 21264248 is about 277.0448041451.

It can be divided in two parts, 21264 and 248, that added together give a palindrome (21512).

The spelling of 21264248 in words is "twenty-one million, two hundred sixty-four thousand, two hundred forty-eight".