1999872709 has 2 divisors, whose sum is σ = 1999872710. Its totient is φ = 1999872708.

The previous prime is 1999872671. The next prime is 1999872727. The reversal of 1999872709 is 9072789991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1466124100 + 533748609 = 38290^2 + 23103^2 .

It is an emirp because it is prime and its reverse (9072789991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1999872709 - 2¹¹ = 1999870661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1999872779) 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, 999936354 + 999936355.

It is an arithmetic number, because the mean of its divisors is an integer number (999936355).

Almost surely, 2^1999872709 is an apocalyptic number.

It is an amenable number.

1999872709 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999872709 is an equidigital number, since it uses as much as digits as its factorization.

1999872709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5143824, while the sum is 61.

The square root of 1999872709 is about 44719.9363707061. The cubic root of 1999872709 is about 1259.8943198927.

The spelling of 1999872709 in words is "one billion, nine hundred ninety-nine million, eight hundred seventy-two thousand, seven hundred nine".