21345264 has 60 divisors (see below), whose sum is σ = 60092136. Its totient is φ = 7072896.

The previous prime is 21345253. The next prime is 21345277. The reversal of 21345264 is 46254312.

21345264 is a `hidden beast` number, since 2 + 134 + 526 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

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, 32362 + ... + 33014.

Almost surely, 2^21345264 is an apocalyptic number.

21345264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21345264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30046068).

21345264 is an abundant number, since it is smaller than the sum of its proper divisors (38746872).

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

21345264 is a wasteful number, since it uses less digits than its factorization.

21345264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 894 (or 885 counting only the distinct ones).

The product of its digits is 5760, while the sum is 27.

The square root of 21345264 is about 4620.0935055473. The cubic root of 21345264 is about 277.3962017442.

Adding to 21345264 its reverse (46254312), we get a palindrome (67599576).

It can be divided in two parts, 21345 and 264, that added together give a square (21609 = 147²).

The spelling of 21345264 in words is "twenty-one million, three hundred forty-five thousand, two hundred sixty-four".