166978905 has 8 divisors (see below), whose sum is σ = 267166272. Its totient is φ = 89055408.

The previous prime is 166978883. The next prime is 166978907. The reversal of 166978905 is 509879661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 166978905 - 2⁶ = 166978841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166978907) by changing a digit.

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, 5565949 + ... + 5565978.

It is an arithmetic number, because the mean of its divisors is an integer number (33395784).

Almost surely, 2^166978905 is an apocalyptic number.

166978905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

166978905 is a deficient number, since it is larger than the sum of its proper divisors (100187367).

166978905 is a wasteful number, since it uses less digits than its factorization.

166978905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11131935.

The product of its (nonzero) digits is 816480, while the sum is 51.

The square root of 166978905 is about 12922.0317674892. The cubic root of 166978905 is about 550.6646565165.

The spelling of 166978905 in words is "one hundred sixty-six million, nine hundred seventy-eight thousand, nine hundred five".