2139561873 has 6 divisors (see below), whose sum is σ = 3090478274. Its totient is φ = 1426374576.

The previous prime is 2139561859. The next prime is 2139561947. The reversal of 2139561873 is 3781659312.

2139561873 is a `hidden beast` number, since 2 + 1 + 3 + 9 + 561 + 87 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1071056529 + 1068505344 = 32727^2 + 32688^2 .

It is not a de Polignac number, because 2139561873 - 2⁵ = 2139561841 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2139561373) 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 5 ways as a sum of consecutive naturals, for example, 118864540 + ... + 118864557.

Almost surely, 2^2139561873 is an apocalyptic number.

It is an amenable number.

2139561873 is a deficient number, since it is larger than the sum of its proper divisors (950916401).

2139561873 is a wasteful number, since it uses less digits than its factorization.

2139561873 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237729103 (or 237729100 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 2139561873 is about 46255.3983119808. The cubic root of 2139561873 is about 1288.5707932082.

The spelling of 2139561873 in words is "two billion, one hundred thirty-nine million, five hundred sixty-one thousand, eight hundred seventy-three".