28961887 has 2 divisors, whose sum is σ = 28961888. Its totient is φ = 28961886.

The previous prime is 28961879. The next prime is 28961929. The reversal of 28961887 is 78816982.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28961887 - 2³ = 28961879 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28961887.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28961837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14480943 + 14480944.

It is an arithmetic number, because the mean of its divisors is an integer number (14480944).

Almost surely, 2^28961887 is an apocalyptic number.

28961887 is a deficient number, since it is larger than the sum of its proper divisors (1).

28961887 is an equidigital number, since it uses as much as digits as its factorization.

28961887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 387072, while the sum is 49.

The square root of 28961887 is about 5381.6249404803. The cubic root of 28961887 is about 307.0970313665.

The spelling of 28961887 in words is "twenty-eight million, nine hundred sixty-one thousand, eight hundred eighty-seven".