2165556660 has 24 divisors (see below), whose sum is σ = 6063558816. Its totient is φ = 577481760.

The previous prime is 2165556641. The next prime is 2165556689. The reversal of 2165556660 is 666555612.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 18046246 + ... + 18046365.

It is an arithmetic number, because the mean of its divisors is an integer number (252648284).

Almost surely, 2^2165556660 is an apocalyptic number.

2165556660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2165556660 is an abundant number, since it is smaller than the sum of its proper divisors (3898002156).

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

2165556660 is a wasteful number, since it uses less digits than its factorization.

2165556660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36092623 (or 36092621 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 42.

The square root of 2165556660 is about 46535.5419007880. The cubic root of 2165556660 is about 1293.7683334703.

The spelling of 2165556660 in words is "two billion, one hundred sixty-five million, five hundred fifty-six thousand, six hundred sixty".