308891 has 4 divisors (see below), whose sum is σ = 336984. Its totient is φ = 280800.

The previous prime is 308887. The next prime is 308899. The reversal of 308891 is 198803.

It is a happy number.

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 308891 - 2² = 308887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (308899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14030 + ... + 14051.

It is an arithmetic number, because the mean of its divisors is an integer number (84246).

2³⁰⁸⁸⁹¹ is an apocalyptic number.

308891 is a deficient number, since it is larger than the sum of its proper divisors (28093).

308891 is a wasteful number, since it uses less digits than its factorization.

308891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28092.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 308891 is about 555.7796325883. The cubic root of 308891 is about 67.5981927087.

The spelling of 308891 in words is "three hundred eight thousand, eight hundred ninety-one".