28438987 has 2 divisors, whose sum is σ = 28438988. Its totient is φ = 28438986.

The previous prime is 28438897. The next prime is 28438999. The reversal of 28438987 is 78983482.

Together with previous prime (28438897) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28438987 - 2¹⁹ = 27914699 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 28438987.

It is not a weakly prime, because it can be changed into another prime (28438187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14219493 + 14219494.

It is an arithmetic number, because the mean of its divisors is an integer number (14219494).

Almost surely, 2^28438987 is an apocalyptic number.

28438987 is a deficient number, since it is larger than the sum of its proper divisors (1).

28438987 is an equidigital number, since it uses as much as digits as its factorization.

28438987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 774144, while the sum is 49.

The square root of 28438987 is about 5332.8216733733. The cubic root of 28438987 is about 305.2376075539.

The spelling of 28438987 in words is "twenty-eight million, four hundred thirty-eight thousand, nine hundred eighty-seven".