166780118077 has 4 divisors (see below), whose sum is σ = 176590713276. Its totient is φ = 156969522880.

The previous prime is 166780118051. The next prime is 166780118101. The reversal of 166780118077 is 770811087661.

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

It can be written as a sum of positive squares in 2 ways, for example, as 85981487076 + 80798631001 = 293226^2 + 284251^2 .

It is a cyclic number.

It is not a de Polignac number, because 166780118077 - 2⁷ = 166780117949 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 (166780118027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4905297574 + ... + 4905297607.

It is an arithmetic number, because the mean of its divisors is an integer number (44147678319).

Almost surely, 2^166780118077 is an apocalyptic number.

166780118077 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

166780118077 is a deficient number, since it is larger than the sum of its proper divisors (9810595199).

166780118077 is an equidigital number, since it uses as much as digits as its factorization.

166780118077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9810595198.

The product of its (nonzero) digits is 790272, while the sum is 52.

The spelling of 166780118077 in words is "one hundred sixty-six billion, seven hundred eighty million, one hundred eighteen thousand, seventy-seven".