285220687 has 4 divisors (see below), whose sum is σ = 285431616. Its totient is φ = 285009760.

The previous prime is 285220673. The next prime is 285220697. The reversal of 285220687 is 786022582.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 786022582 = 2 ⋅393011291.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-285220687 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285220697) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103423 + ... + 106144.

It is an arithmetic number, because the mean of its divisors is an integer number (71357904).

Almost surely, 2^285220687 is an apocalyptic number.

285220687 is a deficient number, since it is larger than the sum of its proper divisors (210929).

285220687 is a wasteful number, since it uses less digits than its factorization.

285220687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210928.

The product of its (nonzero) digits is 107520, while the sum is 40.

The square root of 285220687 is about 16888.4779361552. The cubic root of 285220687 is about 658.2542531442.

The spelling of 285220687 in words is "two hundred eighty-five million, two hundred twenty thousand, six hundred eighty-seven".