28865531 has 4 divisors (see below), whose sum is σ = 28876392. Its totient is φ = 28854672.

The previous prime is 28865521. The next prime is 28865533. The reversal of 28865531 is 13556882.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28865531 - 2⁶ = 28865467 is a prime.

It is a super-2 number, since 2×28865531² = 1666437759823922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28865533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1535 + ... + 7751.

It is an arithmetic number, because the mean of its divisors is an integer number (7219098).

Almost surely, 2^28865531 is an apocalyptic number.

28865531 is a deficient number, since it is larger than the sum of its proper divisors (10861).

28865531 is an equidigital number, since it uses as much as digits as its factorization.

28865531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10860.

The product of its digits is 57600, while the sum is 38.

The square root of 28865531 is about 5372.6651673076. The cubic root of 28865531 is about 306.7560830678.

The spelling of 28865531 in words is "twenty-eight million, eight hundred sixty-five thousand, five hundred thirty-one".