2156771943 has 6 divisors (see below), whose sum is σ = 3115337264. Its totient is φ = 1437847956.

The previous prime is 2156771891. The next prime is 2156771971. The reversal of 2156771943 is 3491776512.

It is not a de Polignac number, because 2156771943 - 2¹⁶ = 2156706407 is a prime.

It is a super-2 number, since 2×2156771943² = 9303330428223990498, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156771993) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 119820655 + ... + 119820672.

Almost surely, 2^2156771943 is an apocalyptic number.

2156771943 is a deficient number, since it is larger than the sum of its proper divisors (958565321).

2156771943 is a wasteful number, since it uses less digits than its factorization.

2156771943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239641333 (or 239641330 counting only the distinct ones).

The product of its digits is 317520, while the sum is 45.

The square root of 2156771943 is about 46441.0588057594. The cubic root of 2156771943 is about 1292.0165450041.

The spelling of 2156771943 in words is "two billion, one hundred fifty-six million, seven hundred seventy-one thousand, nine hundred forty-three".