166388975550 has 96 divisors (see below), whose sum is σ = 523993248000. Its totient is φ = 38031763680.

The previous prime is 166388975531. The next prime is 166388975569. The reversal of 166388975550 is 55579883661.

166388975550 is a `hidden beast` number, since 1 + 6 + 6 + 3 + 8 + 8 + 9 + 75 + 550 = 666.

166388975550 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (166388975531) and next prime (166388975569).

It is a Harshad number since it is a multiple of its sum of digits (63).

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 47 ways as a sum of consecutive naturals, for example, 8794200 + ... + 8813099.

It is an arithmetic number, because the mean of its divisors is an integer number (5458263000).

Almost surely, 2^166388975550 is an apocalyptic number.

166388975550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

166388975550 is an abundant number, since it is smaller than the sum of its proper divisors (357604272450).

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

166388975550 is a wasteful number, since it uses less digits than its factorization.

166388975550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17607327 (or 17607316 counting only the distinct ones).

The product of its (nonzero) digits is 54432000, while the sum is 63.

The spelling of 166388975550 in words is "one hundred sixty-six billion, three hundred eighty-eight million, nine hundred seventy-five thousand, five hundred fifty".