77818 has 16 divisors (see below), whose sum is σ = 130536. Its totient is φ = 34560.

The previous prime is 77813. The next prime is 77839. The reversal of 77818 is 81877.

It can be written as a sum of positive squares in 4 ways, for example, as 34969 + 42849 = 187^2 + 207^2 .

It is a super-2 number, since 2×77818² = 12111282248, which contains 22 as substring.

It is a zygodrome in base 5.

It is a self number, because there is not a number n which added to its sum of digits gives 77818.

It is not an unprimeable number, because it can be changed into a prime (77813) 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, 1030 + ... + 1102.

2⁷⁷⁸¹⁸ is an apocalyptic number.

77818 is a deficient number, since it is larger than the sum of its proper divisors (52718).

77818 is a wasteful number, since it uses less digits than its factorization.

77818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129.

The product of its digits is 3136, while the sum is 31.

The square root of 77818 is about 278.9587783168. The cubic root of 77818 is about 42.6933291467.

The spelling of 77818 in words is "seventy-seven thousand, eight hundred eighteen".