28330557 has 4 divisors (see below), whose sum is σ = 37774080. Its totient is φ = 18887036.

The previous prime is 28330537. The next prime is 28330573. The reversal of 28330557 is 75503382.

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 28330557 - 2⁷ = 28330429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28330537) 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, 4721757 + ... + 4721762.

It is an arithmetic number, because the mean of its divisors is an integer number (9443520).

Almost surely, 2^28330557 is an apocalyptic number.

It is an amenable number.

28330557 is a deficient number, since it is larger than the sum of its proper divisors (9443523).

28330557 is an equidigital number, since it uses as much as digits as its factorization.

28330557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9443522.

The product of its (nonzero) digits is 25200, while the sum is 33.

The square root of 28330557 is about 5322.6456767288. The cubic root of 28330557 is about 304.8491845973.

The spelling of 28330557 in words is "twenty-eight million, three hundred thirty thousand, five hundred fifty-seven".