2139196181 has 4 divisors (see below), whose sum is σ = 2197012332. Its totient is φ = 2081380032.

The previous prime is 2139196153. The next prime is 2139196183. The reversal of 2139196181 is 1816919312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1167315556 + 971880625 = 34166^2 + 31175^2 .

It is a cyclic number.

It is not a de Polignac number, because 2139196181 - 2¹⁸ = 2138934037 is a prime.

It is a super-2 number, since 2×2139196181² = 9152320601609969522, 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 (2139196183) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28908020 + ... + 28908093.

It is an arithmetic number, because the mean of its divisors is an integer number (549253083).

Almost surely, 2^2139196181 is an apocalyptic number.

It is an amenable number.

2139196181 is a deficient number, since it is larger than the sum of its proper divisors (57816151).

2139196181 is an equidigital number, since it uses as much as digits as its factorization.

2139196181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57816150.

The product of its digits is 23328, while the sum is 41.

The square root of 2139196181 is about 46251.4451774212. The cubic root of 2139196181 is about 1288.4973752364.

The spelling of 2139196181 in words is "two billion, one hundred thirty-nine million, one hundred ninety-six thousand, one hundred eighty-one".