2156786361 has 12 divisors (see below), whose sum is σ = 3128288020. Its totient is φ = 1431889920.

The previous prime is 2156786353. The next prime is 2156786363. The reversal of 2156786361 is 1636876512.

2156786361 is a `hidden beast` number, since 2 + 1 + 5 + 6 + 7 + 8 + 636 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1835265600 + 321520761 = 42840^2 + 17931^2 .

It is not a de Polignac number, because 2156786361 - 2³ = 2156786353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2156786363) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 495016 + ... + 499353.

Almost surely, 2^2156786361 is an apocalyptic number.

It is an amenable number.

2156786361 is a deficient number, since it is larger than the sum of its proper divisors (971501659).

2156786361 is a wasteful number, since it uses less digits than its factorization.

2156786361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994616 (or 994613 counting only the distinct ones).

The product of its digits is 362880, while the sum is 45.

The square root of 2156786361 is about 46441.2140345190. The cubic root of 2156786361 is about 1292.0194240371.

The spelling of 2156786361 in words is "two billion, one hundred fifty-six million, seven hundred eighty-six thousand, three hundred sixty-one".