28397987 has 2 divisors, whose sum is σ = 28397988. Its totient is φ = 28397986.

The previous prime is 28397969. The next prime is 28398037. The reversal of 28397987 is 78979382.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28397987 - 2⁶ = 28397923 is a prime.

It is not a weakly prime, because it can be changed into another prime (28397947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14198993 + 14198994.

It is an arithmetic number, because the mean of its divisors is an integer number (14198994).

Almost surely, 2^28397987 is an apocalyptic number.

28397987 is a deficient number, since it is larger than the sum of its proper divisors (1).

28397987 is an equidigital number, since it uses as much as digits as its factorization.

28397987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1524096, while the sum is 53.

The square root of 28397987 is about 5328.9761680833. The cubic root of 28397987 is about 305.0908517309.

The spelling of 28397987 in words is "twenty-eight million, three hundred ninety-seven thousand, nine hundred eighty-seven".