77765 has 8 divisors (see below), whose sum is σ = 94848. Its totient is φ = 61200.

The previous prime is 77761. The next prime is 77773. The reversal of 77765 is 56777.

77765 = 160² + 161² + 162².

It is a happy number.

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

It is not a de Polignac number, because 77765 - 2² = 77761 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77761) 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, 440 + ... + 590.

It is an arithmetic number, because the mean of its divisors is an integer number (11856).

2⁷⁷⁷⁶⁵ is an apocalyptic number.

It is an amenable number.

77765 is a deficient number, since it is larger than the sum of its proper divisors (17083).

77765 is a wasteful number, since it uses less digits than its factorization.

77765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259.

The product of its digits is 10290, while the sum is 32.

The square root of 77765 is about 278.8637660220. The cubic root of 77765 is about 42.6836344731.

It can be divided in two parts, 777 and 65, that multiplied together give a palindrome (50505).

The spelling of 77765 in words is "seventy-seven thousand, seven hundred sixty-five".