28873121665 has 16 divisors (see below), whose sum is σ = 35865089280. Its totient is φ = 22287939520.

The previous prime is 28873121659. The next prime is 28873121701. The reversal of 28873121665 is 56612137882.

It is a happy number.

It is not a de Polignac number, because 28873121665 - 2¹⁵ = 28873088897 is a prime.

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, 171060 + ... + 294970.

It is an arithmetic number, because the mean of its divisors is an integer number (2241568080).

Almost surely, 2^28873121665 is an apocalyptic number.

It is an amenable number.

28873121665 is a deficient number, since it is larger than the sum of its proper divisors (6991967615).

28873121665 is a wasteful number, since it uses less digits than its factorization.

28873121665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125552.

The product of its digits is 967680, while the sum is 49.

The spelling of 28873121665 in words is "twenty-eight billion, eight hundred seventy-three million, one hundred twenty-one thousand, six hundred sixty-five".