1666662500 has 72 divisors (see below), whose sum is σ = 3673889856. Its totient is φ = 661500000.

The previous prime is 1666662469. The next prime is 1666662523. The reversal of 1666662500 is 52666661.

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 23 ways as a sum of consecutive naturals, for example, 1887059 + ... + 1887941.

It is an arithmetic number, because the mean of its divisors is an integer number (51026248).

Almost surely, 2^1666662500 is an apocalyptic number.

1666662500 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 1666662500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1836944928).

1666662500 is an abundant number, since it is smaller than the sum of its proper divisors (2007227356).

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

1666662500 is an equidigital number, since it uses as much as digits as its factorization.

1666662500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063 (or 1041 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 1666662500 is about 40824.7780153181. The cubic root of 1666662500 is about 1185.6301134699.

It can be divided in two parts, 166 and 6662500, that added together give a palindrome (6662666).

The spelling of 1666662500 in words is "one billion, six hundred sixty-six million, six hundred sixty-two thousand, five hundred".