21045835008 has 216 divisors, whose sum is σ = 66342843840. Its totient is φ = 6363463680.

The previous prime is 21045835007. The next prime is 21045835037. The reversal of 21045835008 is 80053854012.

It is a happy number.

21045835008 is a `hidden beast` number, since 21 + 0 + 4 + 583 + 50 + 0 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21045835007) 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 23 ways as a sum of consecutive naturals, for example, 20857608 + ... + 20858616.

Almost surely, 2^21045835008 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 21045835008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33171421920).

21045835008 is an abundant number, since it is smaller than the sum of its proper divisors (45297008832).

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

21045835008 is a wasteful number, since it uses less digits than its factorization.

21045835008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1865 (or 1848 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 36.

The spelling of 21045835008 in words is "twenty-one billion, forty-five million, eight hundred thirty-five thousand, eight".