2605891139 has 4 divisors (see below), whose sum is σ = 2607428424. Its totient is φ = 2604353856.

The previous prime is 2605891109. The next prime is 2605891159. The reversal of 2605891139 is 9311985062.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2605891139 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2605891139.

It is not an unprimeable number, because it can be changed into a prime (2605891109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 766097 + ... + 769490.

It is an arithmetic number, because the mean of its divisors is an integer number (651857106).

Almost surely, 2^2605891139 is an apocalyptic number.

2605891139 is a deficient number, since it is larger than the sum of its proper divisors (1537285).

2605891139 is a wasteful number, since it uses less digits than its factorization.

2605891139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1537284.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 2605891139 is about 51047.9298209046. The cubic root of 2605891139 is about 1376.1066377477.

The spelling of 2605891139 in words is "two billion, six hundred five million, eight hundred ninety-one thousand, one hundred thirty-nine".