28563931 has 8 divisors (see below), whose sum is σ = 31274928. Its totient is φ = 25872000.

The previous prime is 28563929. The next prime is 28563937. The reversal of 28563931 is 13936582.

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

It is not a de Polignac number, because 28563931 - 2¹ = 28563929 is a prime.

It is a super-2 number, since 2×28563931² = 1631796308345522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28563937) 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 7 ways as a sum of consecutive naturals, for example, 1530 + ... + 7711.

It is an arithmetic number, because the mean of its divisors is an integer number (3909366).

Almost surely, 2^28563931 is an apocalyptic number.

28563931 is a deficient number, since it is larger than the sum of its proper divisors (2710997).

28563931 is a wasteful number, since it uses less digits than its factorization.

28563931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9533.

The product of its digits is 38880, while the sum is 37.

The square root of 28563931 is about 5344.5234586444. The cubic root of 28563931 is about 305.6839653682.

The spelling of 28563931 in words is "twenty-eight million, five hundred sixty-three thousand, nine hundred thirty-one".