2091781439 has 16 divisors (see below), whose sum is σ = 2455798176. Its totient is φ = 1760409600.

The previous prime is 2091781427. The next prime is 2091781441. The reversal of 2091781439 is 9341871902.

It is a cyclic number.

It is not a de Polignac number, because 2091781439 - 2⁴ = 2091781423 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 2091781439.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2091781469) 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 15 ways as a sum of consecutive naturals, for example, 80282 + ... + 103095.

It is an arithmetic number, because the mean of its divisors is an integer number (153487386).

Almost surely, 2^2091781439 is an apocalyptic number.

2091781439 is a deficient number, since it is larger than the sum of its proper divisors (364016737).

2091781439 is a wasteful number, since it uses less digits than its factorization.

2091781439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183466.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 2091781439 is about 45735.9971903970. The cubic root of 2091781439 is about 1278.9064225275.

The spelling of 2091781439 in words is "two billion, ninety-one million, seven hundred eighty-one thousand, four hundred thirty-nine".