21145225452 has 24 divisors (see below), whose sum is σ = 53134156656. Its totient is φ = 6506223168.

The previous prime is 21145225397. The next prime is 21145225459. The reversal of 21145225452 is 25452254112.

It is not an unprimeable number, because it can be changed into a prime (21145225459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67773003 + ... + 67773314.

It is an arithmetic number, because the mean of its divisors is an integer number (2213923194).

Almost surely, 2^21145225452 is an apocalyptic number.

It is an amenable number.

21145225452 is an abundant number, since it is smaller than the sum of its proper divisors (31988931204).

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

21145225452 is a wasteful number, since it uses less digits than its factorization.

21145225452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135546337 (or 135546335 counting only the distinct ones).

The product of its digits is 32000, while the sum is 33.

Adding to 21145225452 its reverse (25452254112), we get a palindrome (46597479564).

The spelling of 21145225452 in words is "twenty-one billion, one hundred forty-five million, two hundred twenty-five thousand, four hundred fifty-two".