1948721779 has 2 divisors, whose sum is σ = 1948721780. Its totient is φ = 1948721778.

The previous prime is 1948721777. The next prime is 1948721813. The reversal of 1948721779 is 9771278491.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1948721779 - 2¹ = 1948721777 is a prime.

Together with 1948721777, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1948721777) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 974360889 + 974360890.

It is an arithmetic number, because the mean of its divisors is an integer number (974360890).

Almost surely, 2^1948721779 is an apocalyptic number.

1948721779 is a deficient number, since it is larger than the sum of its proper divisors (1).

1948721779 is an equidigital number, since it uses as much as digits as its factorization.

1948721779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1778112, while the sum is 55.

The square root of 1948721779 is about 44144.3289562770. The cubic root of 1948721779 is about 1249.0599393927.

The spelling of 1948721779 in words is "one billion, nine hundred forty-eight million, seven hundred twenty-one thousand, seven hundred seventy-nine".