166740731778 has 16 divisors (see below), whose sum is σ = 334976898816. Its totient is φ = 55331004720.

The previous prime is 166740731743. The next prime is 166740731783. The reversal of 166740731778 is 877137047661.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62308353 + ... + 62311028.

It is an arithmetic number, because the mean of its divisors is an integer number (20936056176).

Almost surely, 2^166740731778 is an apocalyptic number.

166740731778 is an abundant number, since it is smaller than the sum of its proper divisors (168236167038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166740731778 is a wasteful number, since it uses less digits than its factorization.

166740731778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124619609.

The product of its (nonzero) digits is 8297856, while the sum is 57.

The spelling of 166740731778 in words is "one hundred sixty-six billion, seven hundred forty million, seven hundred thirty-one thousand, seven hundred seventy-eight".