28091668 has 24 divisors (see below), whose sum is σ = 53837280. Its totient is φ = 12719520.

The previous prime is 28091663. The next prime is 28091677. The reversal of 28091668 is 86619082.

It is a super-2 number, since 2×28091668² = 1578283622044448, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28091668.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28091663) 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 7 ways as a sum of consecutive naturals, for example, 11803 + ... + 13981.

It is an arithmetic number, because the mean of its divisors is an integer number (2243220).

Almost surely, 2^28091668 is an apocalyptic number.

It is an amenable number.

28091668 is a deficient number, since it is larger than the sum of its proper divisors (25745612).

28091668 is a wasteful number, since it uses less digits than its factorization.

28091668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2487 (or 2485 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 28091668 is about 5300.1573561546. The cubic root of 28091668 is about 303.9899148316.

The spelling of 28091668 in words is "twenty-eight million, ninety-one thousand, six hundred sixty-eight".