28656987 has 8 divisors (see below), whose sum is σ = 38326080. Its totient is φ = 19046280.

The previous prime is 28656983. The next prime is 28657003. The reversal of 28656987 is 78965682.

28656987 is nontrivially palindromic in base 2.

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

It is not a de Polignac number, because 28656987 - 2² = 28656983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28656983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13437 + ... + 15422.

It is an arithmetic number, because the mean of its divisors is an integer number (4790760).

Almost surely, 2^28656987 is an apocalyptic number.

28656987 is a deficient number, since it is larger than the sum of its proper divisors (9669093).

28656987 is a wasteful number, since it uses less digits than its factorization.

28656987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29193.

The product of its digits is 1451520, while the sum is 51.

The square root of 28656987 is about 5353.2221138301. Note that the first 3 decimals coincide. The cubic root of 28656987 is about 306.0155594634.

The spelling of 28656987 in words is "twenty-eight million, six hundred fifty-six thousand, nine hundred eighty-seven".