28781985 has 8 divisors (see below), whose sum is σ = 46051200. Its totient is φ = 15350384.

The previous prime is 28781971. The next prime is 28782031. The reversal of 28781985 is 58918782.

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 28781985 - 2⁵ = 28781953 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 959385 + ... + 959414.

It is an arithmetic number, because the mean of its divisors is an integer number (5756400).

Almost surely, 2^28781985 is an apocalyptic number.

It is an amenable number.

28781985 is a deficient number, since it is larger than the sum of its proper divisors (17269215).

28781985 is a wasteful number, since it uses less digits than its factorization.

28781985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1918807.

The product of its digits is 322560, while the sum is 48.

The square root of 28781985 is about 5364.8844349156. The cubic root of 28781985 is about 306.4598472913.

The spelling of 28781985 in words is "twenty-eight million, seven hundred eighty-one thousand, nine hundred eighty-five".