228135987791 has 4 divisors (see below), whose sum is σ = 228407902800. Its totient is φ = 227864072784.

The previous prime is 228135987787. The next prime is 228135987799. The reversal of 228135987791 is 197789531822.

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 228135987791 - 2² = 228135987787 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228135987799) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 135956246 + ... + 135957923.

It is an arithmetic number, because the mean of its divisors is an integer number (57101975700).

Almost surely, 2^228135987791 is an apocalyptic number.

228135987791 is a deficient number, since it is larger than the sum of its proper divisors (271915009).

228135987791 is an equidigital number, since it uses as much as digits as its factorization.

228135987791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271915008.

The product of its digits is 15240960, while the sum is 62.

The spelling of 228135987791 in words is "two hundred twenty-eight billion, one hundred thirty-five million, nine hundred eighty-seven thousand, seven hundred ninety-one".