77391 has 6 divisors (see below), whose sum is σ = 111800. Its totient is φ = 51588.

The previous prime is 77383. The next prime is 77417. The reversal of 77391 is 19377.

77391 = 8² + 9² + ... + 61².

It is not a de Polignac number, because 77391 - 2³ = 77383 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 (77351) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4291 + ... + 4308.

2⁷⁷³⁹¹ is an apocalyptic number.

77391 is a deficient number, since it is larger than the sum of its proper divisors (34409).

77391 is a wasteful number, since it uses less digits than its factorization.

77391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8605 (or 8602 counting only the distinct ones).

The product of its digits is 1323, while the sum is 27.

The square root of 77391 is about 278.1923794787. The cubic root of 77391 is about 42.6150974723.

The spelling of 77391 in words is "seventy-seven thousand, three hundred ninety-one".