28397857 has 4 divisors (see below), whose sum is σ = 28532656. Its totient is φ = 28263060.

The previous prime is 28397797. The next prime is 28397861. The reversal of 28397857 is 75879382.

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 28397857 - 2¹⁵ = 28365089 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28397857.

It is not an unprimeable number, because it can be changed into a prime (28397357) 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, 67083 + ... + 67504.

It is an arithmetic number, because the mean of its divisors is an integer number (7133164).

Almost surely, 2^28397857 is an apocalyptic number.

It is an amenable number.

28397857 is a deficient number, since it is larger than the sum of its proper divisors (134799).

28397857 is a wasteful number, since it uses less digits than its factorization.

28397857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134798.

The product of its digits is 846720, while the sum is 49.

The square root of 28397857 is about 5328.9639706044. The cubic root of 28397857 is about 305.0903861830.

The spelling of 28397857 in words is "twenty-eight million, three hundred ninety-seven thousand, eight hundred fifty-seven".