28755691 has 4 divisors (see below), whose sum is σ = 29424472. Its totient is φ = 28086912.

The previous prime is 28755677. The next prime is 28755703. The reversal of 28755691 is 19655782.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28755691 - 2¹⁷ = 28624619 is a prime.

It is a super-3 number, since 3×28755691³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (43), and also a Moran number because the ratio is a prime number: 668737 = 28755691 / (2 + 8 + 7 + 5 + 5 + 6 + 9 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28755641) 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, 334326 + ... + 334411.

It is an arithmetic number, because the mean of its divisors is an integer number (7356118).

Almost surely, 2^28755691 is an apocalyptic number.

28755691 is a deficient number, since it is larger than the sum of its proper divisors (668781).

28755691 is an equidigital number, since it uses as much as digits as its factorization.

28755691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668780.

The product of its digits is 151200, while the sum is 43.

The square root of 28755691 is about 5362.4333096086. The cubic root of 28755691 is about 306.3664959548.

Subtracting from 28755691 its reverse (19655782), we obtain a palindrome (9099909).

The spelling of 28755691 in words is "twenty-eight million, seven hundred fifty-five thousand, six hundred ninety-one".