21530454452 has 24 divisors (see below), whose sum is σ = 40580668296. Its totient is φ = 9936142848.

The previous prime is 21530454391. The next prime is 21530454469. The reversal of 21530454452 is 25445403512.

It can be written as a sum of positive squares in 4 ways, for example, as 4477751056 + 17052703396 = 66916^2 + 130586^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 885368 + ... + 909360.

It is an arithmetic number, because the mean of its divisors is an integer number (1690861179).

Almost surely, 2^21530454452 is an apocalyptic number.

It is an amenable number.

21530454452 is a deficient number, since it is larger than the sum of its proper divisors (19050213844).

21530454452 is a wasteful number, since it uses less digits than its factorization.

21530454452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41267 (or 41265 counting only the distinct ones).

The product of its (nonzero) digits is 96000, while the sum is 35.

Adding to 21530454452 its reverse (25445403512), we get a palindrome (46975857964).

The spelling of 21530454452 in words is "twenty-one billion, five hundred thirty million, four hundred fifty-four thousand, four hundred fifty-two".