28455817 has 4 divisors (see below), whose sum is σ = 30644740. Its totient is φ = 26266896.

The previous prime is 28455743. The next prime is 28455839. The reversal of 28455817 is 71855482.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71855482 = 2 ⋅35927741.

It can be written as a sum of positive squares in 2 ways, for example, as 6702921 + 21752896 = 2589^2 + 4664^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28455817 is a prime.

It is a super-2 number, since 2×28455817² = 1619467042274978, which contains 22 as substring.

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 28455817.

It is not an unprimeable number, because it can be changed into a prime (28455857) 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, 1094442 + ... + 1094467.

It is an arithmetic number, because the mean of its divisors is an integer number (7661185).

Almost surely, 2^28455817 is an apocalyptic number.

It is an amenable number.

28455817 is a deficient number, since it is larger than the sum of its proper divisors (2188923).

28455817 is a wasteful number, since it uses less digits than its factorization.

28455817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2188922.

The product of its digits is 89600, while the sum is 40.

The square root of 28455817 is about 5334.3994038692. The cubic root of 28455817 is about 305.2978081967.

The spelling of 28455817 in words is "twenty-eight million, four hundred fifty-five thousand, eight hundred seventeen".