28551557 has 2 divisors, whose sum is σ = 28551558. Its totient is φ = 28551556.

The previous prime is 28551553. The next prime is 28551563. The reversal of 28551557 is 75515582.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27888961 + 662596 = 5281^2 + 814^2 .

It is a cyclic number.

It is not a de Polignac number, because 28551557 - 2² = 28551553 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28551557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28551553) 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 as a sum of consecutive naturals, namely, 14275778 + 14275779.

It is an arithmetic number, because the mean of its divisors is an integer number (14275779).

Almost surely, 2^28551557 is an apocalyptic number.

It is an amenable number.

28551557 is a deficient number, since it is larger than the sum of its proper divisors (1).

28551557 is an equidigital number, since it uses as much as digits as its factorization.

28551557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 70000, while the sum is 38.

The square root of 28551557 is about 5343.3656996316. The cubic root of 28551557 is about 305.6398178532.

The spelling of 28551557 in words is "twenty-eight million, five hundred fifty-one thousand, five hundred fifty-seven".