28861397 has 4 divisors (see below), whose sum is σ = 28875756. Its totient is φ = 28847040.

The previous prime is 28861381. The next prime is 28861439. The reversal of 28861397 is 79316882.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19704721 + 9156676 = 4439^2 + 3026^2 .

It is a cyclic number.

It is not a de Polignac number, because 28861397 - 2⁴ = 28861381 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 (28861367) 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, 3554 + ... + 8387.

It is an arithmetic number, because the mean of its divisors is an integer number (7218939).

Almost surely, 2^28861397 is an apocalyptic number.

It is an amenable number.

28861397 is a deficient number, since it is larger than the sum of its proper divisors (14359).

28861397 is a wasteful number, since it uses less digits than its factorization.

28861397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14358.

The product of its digits is 145152, while the sum is 44.

The square root of 28861397 is about 5372.2804282725. The cubic root of 28861397 is about 306.7414382632.

The spelling of 28861397 in words is "twenty-eight million, eight hundred sixty-one thousand, three hundred ninety-seven".