77767 has 4 divisors (see below), whose sum is σ = 81880. Its totient is φ = 73656.

The previous prime is 77761. The next prime is 77773. The reversal of 77767 is 76777.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (77761) and next prime (77773).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77767 is a prime.

It is a Duffinian number.

77767 is a lucky number.

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 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, 2028 + ... + 2065.

It is an arithmetic number, because the mean of its divisors is an integer number (20470).

2⁷⁷⁷⁶⁷ is an apocalyptic number.

77767 is a deficient number, since it is larger than the sum of its proper divisors (4113).

77767 is a wasteful number, since it uses less digits than its factorization.

77767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4112.

The product of its digits is 14406, while the sum is 34.

The square root of 77767 is about 278.8673519794. The cubic root of 77767 is about 42.6840003898.

Subtracting from 77767 its reverse (76777), we obtain a triangular number (990 = T₄₄).

The spelling of 77767 in words is "seventy-seven thousand, seven hundred sixty-seven".