228215791 has 4 divisors (see below), whose sum is σ = 228250512. Its totient is φ = 228181072.

The previous prime is 228215789. The next prime is 228215809. The reversal of 228215791 is 197512822.

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 228215791 - 2¹ = 228215789 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 228215791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228210791) 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, 4150 + ... + 21763.

It is an arithmetic number, because the mean of its divisors is an integer number (57062628).

Almost surely, 2^228215791 is an apocalyptic number.

228215791 is a deficient number, since it is larger than the sum of its proper divisors (34721).

228215791 is an equidigital number, since it uses as much as digits as its factorization.

228215791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34720.

The product of its digits is 20160, while the sum is 37.

The square root of 228215791 is about 15106.8127346572. The cubic root of 228215791 is about 611.1041464024.

The spelling of 228215791 in words is "two hundred twenty-eight million, two hundred fifteen thousand, seven hundred ninety-one".