28118861 has 4 divisors (see below), whose sum is σ = 28772832. Its totient is φ = 27464892.

The previous prime is 28118821. The next prime is 28118933. The reversal of 28118861 is 16881182.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16881182 = 2 ⋅8440591.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28118861 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 (28118801) 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, 326921 + ... + 327006.

It is an arithmetic number, because the mean of its divisors is an integer number (7193208).

Almost surely, 2^28118861 is an apocalyptic number.

It is an amenable number.

28118861 is a deficient number, since it is larger than the sum of its proper divisors (653971).

28118861 is an equidigital number, since it uses as much as digits as its factorization.

28118861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653970.

The product of its digits is 6144, while the sum is 35.

The square root of 28118861 is about 5302.7220368411. The cubic root of 28118861 is about 304.0879715682.

The spelling of 28118861 in words is "twenty-eight million, one hundred eighteen thousand, eight hundred sixty-one".