2138440879 has 2 divisors, whose sum is σ = 2138440880. Its totient is φ = 2138440878.

The previous prime is 2138440877. The next prime is 2138440891. The reversal of 2138440879 is 9780448312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2138440879 - 2¹ = 2138440877 is a prime.

Together with 2138440877, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2138440877) 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 as a sum of consecutive naturals, namely, 1069220439 + 1069220440.

It is an arithmetic number, because the mean of its divisors is an integer number (1069220440).

Almost surely, 2^2138440879 is an apocalyptic number.

2138440879 is a deficient number, since it is larger than the sum of its proper divisors (1).

2138440879 is an equidigital number, since it uses as much as digits as its factorization.

2138440879 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 387072, while the sum is 46.

The square root of 2138440879 is about 46243.2792846701. The cubic root of 2138440879 is about 1288.3457109158.

The spelling of 2138440879 in words is "two billion, one hundred thirty-eight million, four hundred forty thousand, eight hundred seventy-nine".