1999979249 has 2 divisors, whose sum is σ = 1999979250. Its totient is φ = 1999979248.

The previous prime is 1999979231. The next prime is 1999979251. The reversal of 1999979249 is 9429799991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1616602849 + 383376400 = 40207^2 + 19580^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1999979249 is a prime.

Together with 1999979251, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1999979269) 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 as a sum of consecutive naturals, namely, 999989624 + 999989625.

It is an arithmetic number, because the mean of its divisors is an integer number (999989625).

Almost surely, 2^1999979249 is an apocalyptic number.

It is an amenable number.

1999979249 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999979249 is an equidigital number, since it uses as much as digits as its factorization.

1999979249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29760696, while the sum is 68.

The square root of 1999979249 is about 44721.1275461610. The cubic root of 1999979249 is about 1259.9166924429.

The spelling of 1999979249 in words is "one billion, nine hundred ninety-nine million, nine hundred seventy-nine thousand, two hundred forty-nine".