77891 has 8 divisors (see below), whose sum is σ = 87024. Its totient is φ = 69120.

The previous prime is 77867. The next prime is 77893. The reversal of 77891 is 19877.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77891 - 2¹⁴ = 61507 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 (77893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 755 + ... + 851.

It is an arithmetic number, because the mean of its divisors is an integer number (10878).

2⁷⁷⁸⁹¹ is an apocalyptic number.

77891 is a deficient number, since it is larger than the sum of its proper divisors (9133).

77891 is a wasteful number, since it uses less digits than its factorization.

77891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181.

The product of its digits is 3528, while the sum is 32.

The square root of 77891 is about 279.0895913502. The cubic root of 77891 is about 42.7066749835.

The spelling of 77891 in words is "seventy-seven thousand, eight hundred ninety-one".