1881291779 has 2 divisors, whose sum is σ = 1881291780. Its totient is φ = 1881291778.

The previous prime is 1881291773. The next prime is 1881291781. The reversal of 1881291779 is 9771921881.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1881291779 is a prime.

Together with 1881291781, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1881291779.

It is not a weakly prime, because it can be changed into another prime (1881291773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 940645889 + 940645890.

It is an arithmetic number, because the mean of its divisors is an integer number (940645890).

Almost surely, 2^1881291779 is an apocalyptic number.

1881291779 is a deficient number, since it is larger than the sum of its proper divisors (1).

1881291779 is an equidigital number, since it uses as much as digits as its factorization.

1881291779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 508032, while the sum is 53.

The square root of 1881291779 is about 43373.8605498750. The cubic root of 1881291779 is about 1234.4837738244.

The spelling of 1881291779 in words is "one billion, eight hundred eighty-one million, two hundred ninety-one thousand, seven hundred seventy-nine".