21052052 has 48 divisors (see below), whose sum is σ = 45577728. Its totient is φ = 8302080.

The previous prime is 21052051. The next prime is 21052063. The reversal of 21052052 is 25025012.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 21052052.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052051) 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, 21902 + ... + 22842.

It is an arithmetic number, because the mean of its divisors is an integer number (949536).

Almost surely, 2^21052052 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 21052052, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22788864).

21052052 is an abundant number, since it is smaller than the sum of its proper divisors (24525676).

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

21052052 is a wasteful number, since it uses less digits than its factorization.

21052052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1016 (or 1014 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 21052052 is about 4588.2515188250. The cubic root of 21052052 is about 276.1201780074.

Adding to 21052052 its reverse (25025012), we get a palindrome (46077064).

The spelling of 21052052 in words is "twenty-one million, fifty-two thousand, fifty-two".