2178397161 has 24 divisors (see below), whose sum is σ = 3220745216. Its totient is φ = 1418420160.

The previous prime is 2178397103. The next prime is 2178397181. The reversal of 2178397161 is 1617938712.

It is not a de Polignac number, because 2178397161 - 2²³ = 2170008553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2178397181) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51576 + ... + 83766.

Almost surely, 2^2178397161 is an apocalyptic number.

It is an amenable number.

2178397161 is a deficient number, since it is larger than the sum of its proper divisors (1042348055).

2178397161 is a wasteful number, since it uses less digits than its factorization.

2178397161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32373 (or 32370 counting only the distinct ones).

The product of its digits is 127008, while the sum is 45.

The square root of 2178397161 is about 46673.3024436883. The cubic root of 2178397161 is about 1296.3203958227.

The spelling of 2178397161 in words is "two billion, one hundred seventy-eight million, three hundred ninety-seven thousand, one hundred sixty-one".