21235636448 has 24 divisors (see below), whose sum is σ = 45023633928. Its totient is φ = 9801062784.

The previous prime is 21235636447. The next prime is 21235636451. The reversal of 21235636448 is 84463653212.

It is a junction number, because it is equal to n+sod(n) for n = 21235636399 and 21235636408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21235636447) 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 3 ways as a sum of consecutive naturals, for example, 25523186 + ... + 25524017.

It is an arithmetic number, because the mean of its divisors is an integer number (1875984747).

Almost surely, 2^21235636448 is an apocalyptic number.

It is an amenable number.

21235636448 is an abundant number, since it is smaller than the sum of its proper divisors (23787997480).

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

21235636448 is a wasteful number, since it uses less digits than its factorization.

21235636448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51047226 (or 51047218 counting only the distinct ones).

The product of its digits is 829440, while the sum is 44.

The spelling of 21235636448 in words is "twenty-one billion, two hundred thirty-five million, six hundred thirty-six thousand, four hundred forty-eight".