28181215775 has 48 divisors (see below), whose sum is σ = 37800794880. Its totient is φ = 20763072000.

The previous prime is 28181215771. The next prime is 28181215789. The reversal of 28181215775 is 57751218182.

It is not a de Polignac number, because 28181215775 - 2² = 28181215771 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28181215771) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5689550 + ... + 5694500.

It is an arithmetic number, because the mean of its divisors is an integer number (787516560).

Almost surely, 2^28181215775 is an apocalyptic number.

28181215775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28181215775 is a deficient number, since it is larger than the sum of its proper divisors (9619579105).

28181215775 is a wasteful number, since it uses less digits than its factorization.

28181215775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5264 (or 5259 counting only the distinct ones).

The product of its digits is 313600, while the sum is 47.

The spelling of 28181215775 in words is "twenty-eight billion, one hundred eighty-one million, two hundred fifteen thousand, seven hundred seventy-five".