28387831 has 8 divisors (see below), whose sum is σ = 28828800. Its totient is φ = 27950520.

The previous prime is 28387787. The next prime is 28387861. The reversal of 28387831 is 13878382.

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

It is a cyclic number.

It is not a de Polignac number, because 28387831 - 2¹¹ = 28385783 is a prime.

It is a super-2 number, since 2×28387831² = 1611737897769122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28387861) 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, 17430 + ... + 18988.

It is an arithmetic number, because the mean of its divisors is an integer number (3603600).

Almost surely, 2^28387831 is an apocalyptic number.

28387831 is a deficient number, since it is larger than the sum of its proper divisors (440969).

28387831 is a wasteful number, since it uses less digits than its factorization.

28387831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1829.

The product of its digits is 64512, while the sum is 40.

The square root of 28387831 is about 5328.0231793790. The cubic root of 28387831 is about 305.0544774140.

The spelling of 28387831 in words is "twenty-eight million, three hundred eighty-seven thousand, eight hundred thirty-one".