21245445052 has 24 divisors (see below), whose sum is σ = 40181002736. Its totient is φ = 9770934528.

The previous prime is 21245445019. The next prime is 21245445059. The reversal of 21245445052 is 25054454212.

It is a junction number, because it is equal to n+sod(n) for n = 21245444999 and 21245445017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21245445059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 707133 + ... + 736564.

Almost surely, 2^21245445052 is an apocalyptic number.

It is an amenable number.

21245445052 is a deficient number, since it is larger than the sum of its proper divisors (18935557684).

21245445052 is a wasteful number, since it uses less digits than its factorization.

21245445052 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1443997 (or 1443995 counting only the distinct ones).

The product of its (nonzero) digits is 64000, while the sum is 34.

Adding to 21245445052 its reverse (25054454212), we get a palindrome (46299899264).

The spelling of 21245445052 in words is "twenty-one billion, two hundred forty-five million, four hundred forty-five thousand, fifty-two".