166523808638 has 8 divisors (see below), whose sum is σ = 272493505080. Its totient is φ = 75692640280.

The previous prime is 166523808623. The next prime is 166523808643. The reversal of 166523808638 is 836808325661.

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3784631993 + ... + 3784632036.

It is an arithmetic number, because the mean of its divisors is an integer number (34061688135).

Almost surely, 2^166523808638 is an apocalyptic number.

166523808638 is a deficient number, since it is larger than the sum of its proper divisors (105969696442).

166523808638 is a wasteful number, since it uses less digits than its factorization.

166523808638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7569264042.

The product of its (nonzero) digits is 9953280, while the sum is 56.

The spelling of 166523808638 in words is "one hundred sixty-six billion, five hundred twenty-three million, eight hundred eight thousand, six hundred thirty-eight".