28091669 has 4 divisors (see below), whose sum is σ = 28203840. Its totient is φ = 27979500.

The previous prime is 28091663. The next prime is 28091677. The reversal of 28091669 is 96619082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28091669 is a prime.

It is a super-2 number, since 2×28091669² = 1578283734411122, 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 (28091663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55709 + ... + 56210.

It is an arithmetic number, because the mean of its divisors is an integer number (7050960).

Almost surely, 2^28091669 is an apocalyptic number.

It is an amenable number.

28091669 is a deficient number, since it is larger than the sum of its proper divisors (112171).

28091669 is a wasteful number, since it uses less digits than its factorization.

28091669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112170.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 28091669 is about 5300.1574504914. The cubic root of 28091669 is about 303.9899184388.

The spelling of 28091669 in words is "twenty-eight million, ninety-one thousand, six hundred sixty-nine".