28491887 has 8 divisors (see below), whose sum is σ = 30802800. Its totient is φ = 26262144.

The previous prime is 28491863. The next prime is 28491893. The reversal of 28491887 is 78819482.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28491887 - 2¹⁰ = 28490863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28490887) 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 7 ways as a sum of consecutive naturals, for example, 19562 + ... + 20967.

It is an arithmetic number, because the mean of its divisors is an integer number (3850350).

Almost surely, 2^28491887 is an apocalyptic number.

28491887 is a deficient number, since it is larger than the sum of its proper divisors (2310913).

28491887 is a wasteful number, since it uses less digits than its factorization.

28491887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40585.

The product of its digits is 258048, while the sum is 47.

The square root of 28491887 is about 5337.7792198629. The cubic root of 28491887 is about 305.4267501082.

The spelling of 28491887 in words is "twenty-eight million, four hundred ninety-one thousand, eight hundred eighty-seven".