21052064 has 36 divisors (see below), whose sum is σ = 45565002. Its totient is φ = 9567360.

The previous prime is 21052063. The next prime is 21052079. The reversal of 21052064 is 46025012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17472400 + 3579664 = 4180^2 + 1892^2 .

It is not an unprimeable number, because it can be changed into a prime (21052063) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1154 + ... + 6590.

Almost surely, 2^21052064 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 21052064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22782501).

21052064 is an abundant number, since it is smaller than the sum of its proper divisors (24512938).

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

21052064 is a wasteful number, since it uses less digits than its factorization.

21052064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5469 (or 5450 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21052064 is about 4588.2528265125. The cubic root of 21052064 is about 276.1202304716.

Adding to 21052064 its reverse (46025012), we get a palindrome (67077076).

The spelling of 21052064 in words is "twenty-one million, fifty-two thousand, sixty-four".