77869 has 4 divisors (see below), whose sum is σ = 84960. Its totient is φ = 70780.

The previous prime is 77867. The next prime is 77893. The reversal of 77869 is 96877.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 96877 = 11 ⋅8807.

It is a cyclic number.

It is not a de Polignac number, because 77869 - 2¹ = 77867 is a prime.

It is a super-2 number, since 2×77869² = 12127162322, which contains 22 as substring.

It is a Duffinian number.

77869 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3529 + ... + 3550.

It is an arithmetic number, because the mean of its divisors is an integer number (21240).

2⁷⁷⁸⁶⁹ is an apocalyptic number.

It is an amenable number.

77869 is a deficient number, since it is larger than the sum of its proper divisors (7091).

77869 is a wasteful number, since it uses less digits than its factorization.

77869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7090.

The product of its digits is 21168, while the sum is 37.

The square root of 77869 is about 279.0501746998. The cubic root of 77869 is about 42.7026538287.

It can be divided in two parts, 77 and 869, that added together give a triangular number (946 = T₄₃).

The spelling of 77869 in words is "seventy-seven thousand, eight hundred sixty-nine".