28347861 has 4 divisors (see below), whose sum is σ = 37797152. Its totient is φ = 18898572.

The previous prime is 28347853. The next prime is 28347863. The reversal of 28347861 is 16874382.

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 not a de Polignac number, because 28347861 - 2³ = 28347853 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 (28347863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4724641 + ... + 4724646.

It is an arithmetic number, because the mean of its divisors is an integer number (9449288).

Almost surely, 2^28347861 is an apocalyptic number.

It is an amenable number.

28347861 is a deficient number, since it is larger than the sum of its proper divisors (9449291).

28347861 is an equidigital number, since it uses as much as digits as its factorization.

28347861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9449290.

The product of its digits is 64512, while the sum is 39.

The square root of 28347861 is about 5324.2709360062. The cubic root of 28347861 is about 304.9112381680.

The spelling of 28347861 in words is "twenty-eight million, three hundred forty-seven thousand, eight hundred sixty-one".