2156115666 has 8 divisors (see below), whose sum is σ = 4312231344. Its totient is φ = 718705220.

The previous prime is 2156115641. The next prime is 2156115701. The reversal of 2156115666 is 6665116512.

It is a sphenic number, since it is the product of 3 distinct primes.

2156115666 is an admirable 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 3 ways as a sum of consecutive naturals, for example, 179676300 + ... + 179676311.

It is an arithmetic number, because the mean of its divisors is an integer number (539028918).

Almost surely, 2^2156115666 is an apocalyptic number.

2156115666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2156115666 is a wasteful number, since it uses less digits than its factorization.

2156115666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359352616.

The product of its digits is 64800, while the sum is 39.

The square root of 2156115666 is about 46433.9925700989. The cubic root of 2156115666 is about 1291.8854838963.

The spelling of 2156115666 in words is "two billion, one hundred fifty-six million, one hundred fifteen thousand, six hundred sixty-six".