166738640 has 20 divisors (see below), whose sum is σ = 387667524. Its totient is φ = 66695424.

The previous prime is 166738639. The next prime is 166738673. The reversal of 166738640 is 46837661.

It can be written as a sum of positive squares in 2 ways, for example, as 36048016 + 130690624 = 6004^2 + 11432^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1042037 + ... + 1042196.

Almost surely, 2^166738640 is an apocalyptic number.

166738640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166738640 is an abundant number, since it is smaller than the sum of its proper divisors (220928884).

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

166738640 is a wasteful number, since it uses less digits than its factorization.

166738640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2084246 (or 2084240 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 41.

The square root of 166738640 is about 12912.7317016966. The cubic root of 166738640 is about 550.4004136523.

The spelling of 166738640 in words is "one hundred sixty-six million, seven hundred thirty-eight thousand, six hundred forty".