2156918771 has 8 divisors (see below), whose sum is σ = 2572226304. Its totient is φ = 1768405320.

The previous prime is 2156918749. The next prime is 2156918791. The reversal of 2156918771 is 1778196512.

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

It is a cyclic number.

It is not a de Polignac number, because 2156918771 - 2¹⁸ = 2156656627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2156918791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6698345 + ... + 6698666.

It is an arithmetic number, because the mean of its divisors is an integer number (321528288).

Almost surely, 2^2156918771 is an apocalyptic number.

2156918771 is a deficient number, since it is larger than the sum of its proper divisors (415307533).

2156918771 is a wasteful number, since it uses less digits than its factorization.

2156918771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13397041.

The product of its digits is 211680, while the sum is 47.

The square root of 2156918771 is about 46442.6395783013. The cubic root of 2156918771 is about 1292.0458634957.

The spelling of 2156918771 in words is "two billion, one hundred fifty-six million, nine hundred eighteen thousand, seven hundred seventy-one".