21515002221115 has 16 divisors (see below), whose sum is σ = 27814467528288. Its totient is φ = 15882021835776.

The previous prime is 21515002221113. The next prime is 21515002221137. The reversal of 21515002221115 is 51112220051512.

It is a cyclic number.

It is not a de Polignac number, because 21515002221115 - 2¹ = 21515002221113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21515002221113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 62115597 + ... + 62461006.

It is an arithmetic number, because the mean of its divisors is an integer number (1738404220518).

Almost surely, 2^{21515002221115} is an apocalyptic number.

21515002221115 is a deficient number, since it is larger than the sum of its proper divisors (6299465307173).

21515002221115 is a wasteful number, since it uses less digits than its factorization.

21515002221115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124579278.

The product of its (nonzero) digits is 2000, while the sum is 28.

Adding to 21515002221115 its reverse (51112220051512), we get a palindrome (72627222272627).

The spelling of 21515002221115 in words is "twenty-one trillion, five hundred fifteen billion, two million, two hundred twenty-one thousand, one hundred fifteen".