2138181807 has 4 divisors (see below), whose sum is σ = 2850909080. Its totient is φ = 1425454536.

The previous prime is 2138181797. The next prime is 2138181839. The reversal of 2138181807 is 7081818312.

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

It is not a de Polignac number, because 2138181807 - 2¹¹ = 2138179759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2138181887) 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, 356363632 + ... + 356363637.

It is an arithmetic number, because the mean of its divisors is an integer number (712727270).

Almost surely, 2^2138181807 is an apocalyptic number.

2138181807 is a deficient number, since it is larger than the sum of its proper divisors (712727273).

2138181807 is an equidigital number, since it uses as much as digits as its factorization.

2138181807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 712727272.

The product of its (nonzero) digits is 21504, while the sum is 39.

The square root of 2138181807 is about 46240.4780143977. The cubic root of 2138181807 is about 1288.2936811429.

The spelling of 2138181807 in words is "two billion, one hundred thirty-eight million, one hundred eighty-one thousand, eight hundred seven".