28180689 has 4 divisors (see below), whose sum is σ = 37574256. Its totient is φ = 18787124.

The previous prime is 28180687. The next prime is 28180699. The reversal of 28180689 is 98608182.

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 28180689 - 2¹ = 28180687 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28180689.

It is not an unprimeable number, because it can be changed into a prime (28180687) 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, 4696779 + ... + 4696784.

It is an arithmetic number, because the mean of its divisors is an integer number (9393564).

Almost surely, 2^28180689 is an apocalyptic number.

It is an amenable number.

28180689 is a deficient number, since it is larger than the sum of its proper divisors (9393567).

28180689 is an equidigital number, since it uses as much as digits as its factorization.

28180689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9393566.

The product of its (nonzero) digits is 55296, while the sum is 42.

The square root of 28180689 is about 5308.5486717181. The cubic root of 28180689 is about 304.3106855190.

The spelling of 28180689 in words is "twenty-eight million, one hundred eighty thousand, six hundred eighty-nine".