2166665760 has 576 divisors, whose sum is σ = 9246182400. Its totient is φ = 468052992.

The previous prime is 2166665747. The next prime is 2166665789. The reversal of 2166665760 is 675666612.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5170831 + ... + 5171249.

It is an arithmetic number, because the mean of its divisors is an integer number (16052400).

Almost surely, 2^2166665760 is an apocalyptic number.

2166665760 is a gapful number since it is divisible by the number (20) 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 2166665760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4623091200).

2166665760 is an abundant number, since it is smaller than the sum of its proper divisors (7079516640).

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

2166665760 is a wasteful number, since it uses less digits than its factorization.

2166665760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475 (or 455 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 2166665760 is about 46547.4570733998. The cubic root of 2166665760 is about 1293.9891656144.

The spelling of 2166665760 in words is "two billion, one hundred sixty-six million, six hundred sixty-five thousand, seven hundred sixty".