21215035044 has 216 divisors, whose sum is σ = 65576102592. Its totient is φ = 5661532800.

The previous prime is 21215035033. The next prime is 21215035069. The reversal of 21215035044 is 44053051212.

21215035044 is a `hidden beast` number, since 2 + 1 + 2 + 150 + 3 + 504 + 4 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21215034999 and 21215035017.

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 5730394 + ... + 5734094.

Almost surely, 2^21215035044 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 21215035044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32788051296).

21215035044 is an abundant number, since it is smaller than the sum of its proper divisors (44361067548).

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

21215035044 is a wasteful number, since it uses less digits than its factorization.

21215035044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3807 (or 3779 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 21215035044 its reverse (44053051212), we get a palindrome (65268086256).

The spelling of 21215035044 in words is "twenty-one billion, two hundred fifteen million, thirty-five thousand, forty-four".