21509118303312 has 80 divisors (see below), whose sum is σ = 58837747393152. Its totient is φ = 6747501895680.

The previous prime is 21509118303269. The next prime is 21509118303331. The reversal of 21509118303312 is 21330381190512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11271237 + ... + 13040667.

Almost surely, 2^{21509118303312} is an apocalyptic number.

It is an amenable number.

21509118303312 is an abundant number, since it is smaller than the sum of its proper divisors (37328629089840).

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

21509118303312 is a wasteful number, since it uses less digits than its factorization.

21509118303312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1784356 (or 1784350 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

Adding to 21509118303312 its reverse (21330381190512), we get a palindrome (42839499493824).

The spelling of 21509118303312 in words is "twenty-one trillion, five hundred nine billion, one hundred eighteen million, three hundred three thousand, three hundred twelve".