787891 has 4 divisors (see below), whose sum is σ = 848512. Its totient is φ = 727272.

The previous prime is 787883. The next prime is 787903. The reversal of 787891 is 198787.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 198787 = 137 ⋅1451.

It is not a de Polignac number, because 787891 - 2³ = 787883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (787811) 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, 30291 + ... + 30316.

It is an arithmetic number, because the mean of its divisors is an integer number (212128).

2⁷⁸⁷⁸⁹¹ is an apocalyptic number.

787891 is a deficient number, since it is larger than the sum of its proper divisors (60621).

787891 is a wasteful number, since it uses less digits than its factorization.

787891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60620.

The product of its digits is 28224, while the sum is 40.

The square root of 787891 is about 887.6322436685. The cubic root of 787891 is about 92.3610184575.

The spelling of 787891 in words is "seven hundred eighty-seven thousand, eight hundred ninety-one".