2166541578 has 24 divisors (see below), whose sum is σ = 4845599616. Its totient is φ = 698884200.

The previous prime is 2166541577. The next prime is 2166541589. The reversal of 2166541578 is 8751456612.

2166541578 is a `hidden beast` number, since 2 + 16 + 65 + 4 + 1 + 578 = 666.

It is not an unprimeable number, because it can be changed into a prime (2166541577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1940788 + ... + 1941903.

It is an arithmetic number, because the mean of its divisors is an integer number (201899984).

Almost surely, 2^2166541578 is an apocalyptic number.

2166541578 is an abundant number, since it is smaller than the sum of its proper divisors (2679058038).

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

2166541578 is a wasteful number, since it uses less digits than its factorization.

2166541578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3882730 (or 3882727 counting only the distinct ones).

The product of its digits is 403200, while the sum is 45.

The square root of 2166541578 is about 46546.1231253474. The cubic root of 2166541578 is about 1293.9644435683.

The spelling of 2166541578 in words is "two billion, one hundred sixty-six million, five hundred forty-one thousand, five hundred seventy-eight".