28311117 has 4 divisors (see below), whose sum is σ = 37748160. Its totient is φ = 18874076.

The previous prime is 28311113. The next prime is 28311119. The reversal of 28311117 is 71111382.

It is a happy number.

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 28311117 - 2² = 28311113 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28311113) 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, 4718517 + ... + 4718522.

It is an arithmetic number, because the mean of its divisors is an integer number (9437040).

Almost surely, 2^28311117 is an apocalyptic number.

It is an amenable number.

28311117 is a deficient number, since it is larger than the sum of its proper divisors (9437043).

28311117 is an equidigital number, since it uses as much as digits as its factorization.

28311117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9437042.

The product of its digits is 336, while the sum is 24.

The square root of 28311117 is about 5320.8192038445. The cubic root of 28311117 is about 304.7794410083.

Adding to 28311117 its reverse (71111382), we get a palindrome (99422499).

It can be divided in two parts, 283111 and 17, that added together give a triangular number (283128 = T₇₅₂).

The spelling of 28311117 in words is "twenty-eight million, three hundred eleven thousand, one hundred seventeen".