28917985 has 8 divisors (see below), whose sum is σ = 34742376. Its totient is φ = 23107200.

The previous prime is 28917953. The next prime is 28918031. The reversal of 28917985 is 58971982.

It can be written as a sum of positive squares in 4 ways, for example, as 16329681 + 12588304 = 4041^2 + 3548^2 .

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

It is not a de Polignac number, because 28917985 - 2⁵ = 28917953 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2085 + ... + 7885.

It is an arithmetic number, because the mean of its divisors is an integer number (4342797).

Almost surely, 2^28917985 is an apocalyptic number.

It is an amenable number.

28917985 is a deficient number, since it is larger than the sum of its proper divisors (5824391).

28917985 is an equidigital number, since it uses as much as digits as its factorization.

28917985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6803.

The product of its digits is 362880, while the sum is 49.

The square root of 28917985 is about 5377.5445139952. The cubic root of 28917985 is about 306.9417814462.

The spelling of 28917985 in words is "twenty-eight million, nine hundred seventeen thousand, nine hundred eighty-five".