28398861 has 6 divisors (see below), whose sum is σ = 41020590. Its totient is φ = 18932568.

The previous prime is 28398847. The next prime is 28398889. The reversal of 28398861 is 16889382.

It can be written as a sum of positive squares in only one way, i.e., 22610025 + 5788836 = 4755^2 + 2406^2 .

It is not a de Polignac number, because 28398861 - 2⁵ = 28398829 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28398661) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1577706 + ... + 1577723.

It is an arithmetic number, because the mean of its divisors is an integer number (6836765).

Almost surely, 2^28398861 is an apocalyptic number.

It is an amenable number.

28398861 is a deficient number, since it is larger than the sum of its proper divisors (12621729).

28398861 is a wasteful number, since it uses less digits than its factorization.

28398861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3155435 (or 3155432 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 28398861 is about 5329.0581719475. The cubic root of 28398861 is about 305.0939816085.

The spelling of 28398861 in words is "twenty-eight million, three hundred ninety-eight thousand, eight hundred sixty-one".