28399887 has 24 divisors (see below), whose sum is σ = 41901600. Its totient is φ = 18532800.

The previous prime is 28399873. The next prime is 28399901. The reversal of 28399887 is 78899382.

It is an interprime number because it is at equal distance from previous prime (28399873) and next prime (28399901).

It is not a de Polignac number, because 28399887 - 2¹² = 28395791 is a prime.

It is a super-2 number, since 2×28399887² = 1613107163225538, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28399807) 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 in 23 ways as a sum of consecutive naturals, for example, 142614 + ... + 142812.

It is an arithmetic number, because the mean of its divisors is an integer number (1745900).

Almost surely, 2^28399887 is an apocalyptic number.

28399887 is a deficient number, since it is larger than the sum of its proper divisors (13501713).

28399887 is a wasteful number, since it uses less digits than its factorization.

28399887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463 (or 460 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

The square root of 28399887 is about 5329.1544357431. The cubic root of 28399887 is about 305.0976557307.

The spelling of 28399887 in words is "twenty-eight million, three hundred ninety-nine thousand, eight hundred eighty-seven".