28888669 has 4 divisors (see below), whose sum is σ = 29884860. Its totient is φ = 27892480.

The previous prime is 28888663. The next prime is 28888681. The reversal of 28888669 is 96688882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 96688882 = 2 ⋅48344441.

It can be written as a sum of positive squares in 2 ways, for example, as 8773444 + 20115225 = 2962^2 + 4485^2 .

It is a cyclic number.

It is not a de Polignac number, because 28888669 - 2¹⁵ = 28855901 is a prime.

It is a super-2 number, since 2×28888669² = 1669110393183122, 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 (28888663) 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, 498052 + ... + 498109.

It is an arithmetic number, because the mean of its divisors is an integer number (7471215).

Almost surely, 2^28888669 is an apocalyptic number.

28888669 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28888669 is a deficient number, since it is larger than the sum of its proper divisors (996191).

28888669 is an equidigital number, since it uses as much as digits as its factorization.

28888669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 996190.

The product of its digits is 2654208, while the sum is 55.

The square root of 28888669 is about 5374.8180434318. The cubic root of 28888669 is about 306.8380242434.

The spelling of 28888669 in words is "twenty-eight million, eight hundred eighty-eight thousand, six hundred sixty-nine".