28215912887 has 4 divisors (see below), whose sum is σ = 28268068536. Its totient is φ = 28163757240.

The previous prime is 28215912863. The next prime is 28215912919. The reversal of 28215912887 is 78821951282.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28215912887 - 2²⁰ = 28214864311 is a prime.

It is a super-2 number, since 2×28215912887² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28215912827) 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 3 ways as a sum of consecutive naturals, for example, 26077013 + ... + 26078094.

It is an arithmetic number, because the mean of its divisors is an integer number (7067017134).

Almost surely, 2^28215912887 is an apocalyptic number.

28215912887 is a deficient number, since it is larger than the sum of its proper divisors (52155649).

28215912887 is an equidigital number, since it uses as much as digits as its factorization.

28215912887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52155648.

The product of its digits is 1290240, while the sum is 53.

The spelling of 28215912887 in words is "twenty-eight billion, two hundred fifteen million, nine hundred twelve thousand, eight hundred eighty-seven".