28491866 has 8 divisors (see below), whose sum is σ = 46025364. Its totient is φ = 13150080.

The previous prime is 28491863. The next prime is 28491893. The reversal of 28491866 is 66819482.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 23804641 + 4687225 = 4879^2 + 2165^2 .

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

It is not an unprimeable number, because it can be changed into a prime (28491863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 547895 + ... + 547946.

Almost surely, 2^28491866 is an apocalyptic number.

28491866 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

28491866 is a deficient number, since it is larger than the sum of its proper divisors (17533498).

28491866 is a wasteful number, since it uses less digits than its factorization.

28491866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1095856.

The product of its digits is 165888, while the sum is 44.

The square root of 28491866 is about 5337.7772527523. Note that the first 3 decimals coincide. The cubic root of 28491866 is about 305.4266750698.

The spelling of 28491866 in words is "twenty-eight million, four hundred ninety-one thousand, eight hundred sixty-six".