28691117 has 24 divisors (see below), whose sum is σ = 36494136. Its totient is φ = 22353408.

The previous prime is 28691107. The next prime is 28691123. The reversal of 28691117 is 71119682.

It can be written as a sum of positive squares in 4 ways, for example, as 164836 + 28526281 = 406^2 + 5341^2 .

It is not a de Polignac number, because 28691117 - 2²⁰ = 27642541 is a prime.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28691107) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46193 + ... + 46809.

It is an arithmetic number, because the mean of its divisors is an integer number (1520589).

Almost surely, 2^28691117 is an apocalyptic number.

It is an amenable number.

28691117 is a deficient number, since it is larger than the sum of its proper divisors (7803019).

28691117 is a wasteful number, since it uses less digits than its factorization.

28691117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717 (or 710 counting only the distinct ones).

The product of its digits is 6048, while the sum is 35.

The square root of 28691117 is about 5356.4089649690. The cubic root of 28691117 is about 306.1369977646.

The spelling of 28691117 in words is "twenty-eight million, six hundred ninety-one thousand, one hundred seventeen".