2166122820 has 48 divisors (see below), whose sum is σ = 6229073088. Its totient is φ = 562020480.

The previous prime is 2166122731. The next prime is 2166122831. The reversal of 2166122820 is 282216612.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 485646 + ... + 490085.

It is an arithmetic number, because the mean of its divisors is an integer number (129772356).

Almost surely, 2^2166122820 is an apocalyptic number.

2166122820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2166122820 is an abundant number, since it is smaller than the sum of its proper divisors (4062950268).

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

2166122820 is a wasteful number, since it uses less digits than its factorization.

2166122820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 975780 (or 975778 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 2166122820 is about 46541.6245956241. The cubic root of 2166122820 is about 1293.8810706200.

The spelling of 2166122820 in words is "two billion, one hundred sixty-six million, one hundred twenty-two thousand, eight hundred twenty".