28218577 has 4 divisors (see below), whose sum is σ = 28241920. Its totient is φ = 28195236.

The previous prime is 28218571. The next prime is 28218583. The reversal of 28218577 is 77581282.

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 an interprime number because it is at equal distance from previous prime (28218571) and next prime (28218583).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28218577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28218571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9753 + ... + 12310.

It is an arithmetic number, because the mean of its divisors is an integer number (7060480).

Almost surely, 2^28218577 is an apocalyptic number.

It is an amenable number.

28218577 is a deficient number, since it is larger than the sum of its proper divisors (23343).

28218577 is a wasteful number, since it uses less digits than its factorization.

28218577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23342.

The product of its digits is 62720, while the sum is 40.

The square root of 28218577 is about 5312.1160567141. The cubic root of 28218577 is about 304.4470029809.

The spelling of 28218577 in words is "twenty-eight million, two hundred eighteen thousand, five hundred seventy-seven".