21602052 has 60 divisors (see below), whose sum is σ = 57450316. Its totient is φ = 7076160.

The previous prime is 21602041. The next prime is 21602059. The reversal of 21602052 is 25020612.

It can be written as a sum of positive squares in 2 ways, for example, as 11451456 + 10150596 = 3384^2 + 3186^2 .

It is a super-2 number, since 2×21602052² = 933297301221408, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (21602059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 19218 + ... + 20310.

Almost surely, 2^21602052 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 21602052, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28725158).

21602052 is an abundant number, since it is smaller than the sum of its proper divisors (35848264).

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

21602052 is a wasteful number, since it uses less digits than its factorization.

21602052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1170 (or 1159 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21602052 is about 4647.8007702568. The cubic root of 21602052 is about 278.5041487563.

Adding to 21602052 its reverse (25020612), we get a palindrome (46622664).

The spelling of 21602052 in words is "twenty-one million, six hundred two thousand, fifty-two".