16666661700 has 216 divisors, whose sum is σ = 56598851400. Its totient is φ = 4102076160.

The previous prime is 16666661689. The next prime is 16666661749. The reversal of 16666661700 is 716666661.

It can be written as a sum of positive squares in 12 ways, for example, as 16404998724 + 261662976 = 128082^2 + 16176^2 .

It is a super-2 number, since 2×16666661700² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1973086 + ... + 1981514.

Almost surely, 2^16666661700 is an apocalyptic number.

16666661700 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 16666661700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28299425700).

16666661700 is an abundant number, since it is smaller than the sum of its proper divisors (39932189700).

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

16666661700 is a wasteful number, since it uses less digits than its factorization.

16666661700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8488 (or 8452 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The spelling of 16666661700 in words is "sixteen billion, six hundred sixty-six million, six hundred sixty-one thousand, seven hundred".