21043515255 has 48 divisors (see below), whose sum is σ = 39233566944. Its totient is φ = 9603471360.

The previous prime is 21043515217. The next prime is 21043515271. The reversal of 21043515255 is 55251534012.

It is not a de Polignac number, because 21043515255 - 2¹³ = 21043507063 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 411715 + ... + 459995.

It is an arithmetic number, because the mean of its divisors is an integer number (817365978).

Almost surely, 2^21043515255 is an apocalyptic number.

21043515255 is a deficient number, since it is larger than the sum of its proper divisors (18190051689).

21043515255 is a wasteful number, since it uses less digits than its factorization.

21043515255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48896 (or 48889 counting only the distinct ones).

The product of its (nonzero) digits is 30000, while the sum is 33.

The spelling of 21043515255 in words is "twenty-one billion, forty-three million, five hundred fifteen thousand, two hundred fifty-five".