166666500 has 576 divisors, whose sum is σ = 725018112. Its totient is φ = 31104000.

The previous prime is 166666481. The next prime is 166666547. The reversal of 166666500 is 5666661.

166666500 = T₁ + T₂ + ... + T₉₉₉.

166666500 is a nontrivial binomial coefficient, being equal to C(1001, 3).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is the 999-th tetrahedral number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 4504482 + ... + 4504518.

It is an arithmetic number, because the mean of its divisors is an integer number (1258712).

Almost surely, 2^166666500 is an apocalyptic number.

166666500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166666500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (362509056).

166666500 is an abundant number, since it is smaller than the sum of its proper divisors (558351612).

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

166666500 is a wasteful number, since it uses less digits than its factorization.

166666500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 166666500 is about 12909.9380323842. The cubic root of 166666500 is about 550.3210247086.

It can be divided in two parts, 166 and 666500, that added together give a palindrome (666666).

The spelling of 166666500 in words is "one hundred sixty-six million, six hundred sixty-six thousand, five hundred".