28721999215 has 16 divisors (see below), whose sum is σ = 42420184128. Its totient is φ = 18180078336.

The previous prime is 28721999203. The next prime is 28721999279. The reversal of 28721999215 is 51299912782.

It is not a de Polignac number, because 28721999215 - 2²¹ = 28719902063 is a prime.

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, 31562182 + ... + 31563091.

It is an arithmetic number, because the mean of its divisors is an integer number (2651261508).

Almost surely, 2^28721999215 is an apocalyptic number.

28721999215 is a deficient number, since it is larger than the sum of its proper divisors (13698184913).

28721999215 is a wasteful number, since it uses less digits than its factorization.

28721999215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63125298.

The product of its digits is 1632960, while the sum is 55.

The spelling of 28721999215 in words is "twenty-eight billion, seven hundred twenty-one million, nine hundred ninety-nine thousand, two hundred fifteen".