228131729 has 4 divisors (see below), whose sum is σ = 260721984. Its totient is φ = 195541476.

The previous prime is 228131699. The next prime is 228131731. The reversal of 228131729 is 927131822.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 228131729 - 2⁸ = 228131473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (228131329) 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, 16295117 + ... + 16295130.

It is an arithmetic number, because the mean of its divisors is an integer number (65180496).

Almost surely, 2^228131729 is an apocalyptic number.

It is an amenable number.

228131729 is a deficient number, since it is larger than the sum of its proper divisors (32590255).

228131729 is an equidigital number, since it uses as much as digits as its factorization.

228131729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32590254.

The product of its digits is 12096, while the sum is 35.

The square root of 228131729 is about 15104.0302237515. The cubic root of 228131729 is about 611.0291049323.

It can be divided in two parts, 22813 and 1729, that added together give a palindrome (24542).

The spelling of 228131729 in words is "two hundred twenty-eight million, one hundred thirty-one thousand, seven hundred twenty-nine".