21515163505 has 8 divisors (see below), whose sum is σ = 28165305024. Its totient is φ = 15647391600.

The previous prime is 21515163479. The next prime is 21515163529. The reversal of 21515163505 is 50536151512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21515163505 - 2⁷ = 21515163377 is a prime.

It is a Duffinian number.

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 7 ways as a sum of consecutive naturals, for example, 195592341 + ... + 195592450.

It is an arithmetic number, because the mean of its divisors is an integer number (3520663128).

Almost surely, 2^21515163505 is an apocalyptic number.

It is an amenable number.

21515163505 is a deficient number, since it is larger than the sum of its proper divisors (6650141519).

21515163505 is a wasteful number, since it uses less digits than its factorization.

21515163505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391184807.

The product of its (nonzero) digits is 22500, while the sum is 34.

The spelling of 21515163505 in words is "twenty-one billion, five hundred fifteen million, one hundred sixty-three thousand, five hundred five".