2166975720 has 512 divisors, whose sum is σ = 9420364800. Its totient is φ = 429981696.

The previous prime is 2166975691. The next prime is 2166975721. The reversal of 2166975720 is 275796612.

2166975720 is a `hidden beast` number, since 2 + 16 + 69 + 7 + 572 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (2166975721) by changing a digit.

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 127 ways as a sum of consecutive naturals, for example, 1670112 + ... + 1671408.

It is an arithmetic number, because the mean of its divisors is an integer number (18399150).

Almost surely, 2^2166975720 is an apocalyptic number.

2166975720 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 2166975720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4710182400).

2166975720 is an abundant number, since it is smaller than the sum of its proper divisors (7253389080).

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

2166975720 is a wasteful number, since it uses less digits than its factorization.

2166975720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1354 (or 1344 counting only the distinct ones).

The product of its (nonzero) digits is 317520, while the sum is 45.

The square root of 2166975720 is about 46550.7864595218. The cubic root of 2166975720 is about 1294.0508680644.

The spelling of 2166975720 in words is "two billion, one hundred sixty-six million, nine hundred seventy-five thousand, seven hundred twenty".