28557577 has 4 divisors (see below), whose sum is σ = 29025796. Its totient is φ = 28089360.

The previous prime is 28557553. The next prime is 28557643. The reversal of 28557577 is 77575582.

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 456976 + 28100601 = 676^2 + 5301^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28557577 is a prime.

It is a super-2 number, since 2×28557577² = 1631070408221858, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28557077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234018 + ... + 234139.

It is an arithmetic number, because the mean of its divisors is an integer number (7256449).

Almost surely, 2^28557577 is an apocalyptic number.

It is an amenable number.

28557577 is a deficient number, since it is larger than the sum of its proper divisors (468219).

28557577 is an equidigital number, since it uses as much as digits as its factorization.

28557577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468218.

The product of its digits is 686000, while the sum is 46.

The square root of 28557577 is about 5343.9289853066. The cubic root of 28557577 is about 305.6612973870.

The spelling of 28557577 in words is "twenty-eight million, five hundred fifty-seven thousand, five hundred seventy-seven".