21445452 has 96 divisors (see below), whose sum is σ = 66931200. Its totient is φ = 5800896.

The previous prime is 21445451. The next prime is 21445469. The reversal of 21445452 is 25454412.

It is a super-2 number, since 2×21445452² = 919814822968608, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21445451) 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 31 ways as a sum of consecutive naturals, for example, 13618 + ... + 15110.

It is an arithmetic number, because the mean of its divisors is an integer number (697200).

Almost surely, 2^21445452 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 21445452, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33465600).

21445452 is an abundant number, since it is smaller than the sum of its proper divisors (45485748).

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

21445452 is a wasteful number, since it uses less digits than its factorization.

21445452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1532 (or 1524 counting only the distinct ones).

The product of its digits is 6400, while the sum is 27.

The square root of 21445452 is about 4630.9234500259. The cubic root of 21445452 is about 277.8295281834.

Adding to 21445452 its reverse (25454412), we get a palindrome (46899864).

The spelling of 21445452 in words is "twenty-one million, four hundred forty-five thousand, four hundred fifty-two".