2156115665 has 8 divisors (see below), whose sum is σ = 2822551488. Its totient is φ = 1568084080.

The previous prime is 2156115641. The next prime is 2156115701. The reversal of 2156115665 is 5665116512.

It is a happy number.

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

It is not a de Polignac number, because 2156115665 - 2⁶ = 2156115601 is a prime.

It is a Duffinian number.

It is a Curzon 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, 19600997 + ... + 19601106.

It is an arithmetic number, because the mean of its divisors is an integer number (352818936).

Almost surely, 2^2156115665 is an apocalyptic number.

It is an amenable number.

2156115665 is a deficient number, since it is larger than the sum of its proper divisors (666435823).

2156115665 is a wasteful number, since it uses less digits than its factorization.

2156115665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39202119.

The product of its digits is 54000, while the sum is 38.

The square root of 2156115665 is about 46433.9925593309. The cubic root of 2156115665 is about 1291.8854836965.

The spelling of 2156115665 in words is "two billion, one hundred fifty-six million, one hundred fifteen thousand, six hundred sixty-five".