28371557 has 2 divisors, whose sum is σ = 28371558. Its totient is φ = 28371556.

The previous prime is 28371533. The next prime is 28371559. The reversal of 28371557 is 75517382.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28206721 + 164836 = 5311^2 + 406^2 .

It is a cyclic number.

It is not a de Polignac number, because 28371557 - 2⁶ = 28371493 is a prime.

Together with 28371559, it forms a pair of twin primes.

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 28371557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28371559) 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, 14185778 + 14185779.

It is an arithmetic number, because the mean of its divisors is an integer number (14185779).

Almost surely, 2^28371557 is an apocalyptic number.

It is an amenable number.

28371557 is a deficient number, since it is larger than the sum of its proper divisors (1).

28371557 is an equidigital number, since it uses as much as digits as its factorization.

28371557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58800, while the sum is 38.

The square root of 28371557 is about 5326.4957523685. The cubic root of 28371557 is about 304.9961730237.

The spelling of 28371557 in words is "twenty-eight million, three hundred seventy-one thousand, five hundred fifty-seven".