428987 has 4 divisors (see below), whose sum is σ = 462000. Its totient is φ = 395976.

The previous prime is 428977. The next prime is 429007. The reversal of 428987 is 789824.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 428987 - 2⁸ = 428731 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 428987.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 428987.

It is not an unprimeable number, because it can be changed into a prime (428957) 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, 16487 + ... + 16512.

It is an arithmetic number, because the mean of its divisors is an integer number (115500).

2⁴²⁸⁹⁸⁷ is an apocalyptic number.

428987 is a deficient number, since it is larger than the sum of its proper divisors (33013).

428987 is a wasteful number, since it uses less digits than its factorization.

428987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33012.

The product of its digits is 32256, while the sum is 38.

The square root of 428987 is about 654.9709917241. The cubic root of 428987 is about 75.4191054972.

Adding to 428987 its sum of digits (38), we get a square (429025 = 655²).

The spelling of 428987 in words is "four hundred twenty-eight thousand, nine hundred eighty-seven".