28687897 has 4 divisors (see below), whose sum is σ = 32786176. Its totient is φ = 24589620.

The previous prime is 28687889. The next prime is 28687909. The reversal of 28687897 is 79878682.

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 28687897 - 2³ = 28687889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28687807) 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, 2049129 + ... + 2049142.

It is an arithmetic number, because the mean of its divisors is an integer number (8196544).

Almost surely, 2^28687897 is an apocalyptic number.

It is an amenable number.

28687897 is a deficient number, since it is larger than the sum of its proper divisors (4098279).

28687897 is an equidigital number, since it uses as much as digits as its factorization.

28687897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4098278.

The product of its digits is 2709504, while the sum is 55.

The square root of 28687897 is about 5356.1083820251. The cubic root of 28687897 is about 306.1255447655.

It can be divided in two parts, 28687 and 897, that added together give a square (29584 = 172²).

The spelling of 28687897 in words is "twenty-eight million, six hundred eighty-seven thousand, eight hundred ninety-seven".