28695991 has 4 divisors (see below), whose sum is σ = 29306592. Its totient is φ = 28085392.

The previous prime is 28695977. The next prime is 28696037. The reversal of 28695991 is 19959682.

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

It is a cyclic number.

It is not a de Polignac number, because 28695991 - 2⁵ = 28695959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28695391) 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, 305230 + ... + 305323.

It is an arithmetic number, because the mean of its divisors is an integer number (7326648).

Almost surely, 2^28695991 is an apocalyptic number.

28695991 is a deficient number, since it is larger than the sum of its proper divisors (610601).

28695991 is an equidigital number, since it uses as much as digits as its factorization.

28695991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610600.

The product of its digits is 349920, while the sum is 49.

The square root of 28695991 is about 5356.8639146426. The cubic root of 28695991 is about 306.1543321337.

The spelling of 28695991 in words is "twenty-eight million, six hundred ninety-five thousand, nine hundred ninety-one".