1938899999 has 2 divisors, whose sum is σ = 1938900000. Its totient is φ = 1938899998.

The previous prime is 1938899993. The next prime is 1938900001. The reversal of 1938899999 is 9999988391.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1938899999 - 2¹⁶ = 1938834463 is a prime.

It is a super-2 number, since 2×1938899999² = 7518666412244400002, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1938900001, it forms a pair of twin primes.

It is a Chen prime.

1938899999 is a modest number, since divided by 99999 gives 19388 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1938899993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 969449999 + 969450000.

It is an arithmetic number, because the mean of its divisors is an integer number (969450000).

Almost surely, 2^1938899999 is an apocalyptic number.

1938899999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1938899999 is an equidigital number, since it uses as much as digits as its factorization.

1938899999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 102036672, while the sum is 74.

The square root of 1938899999 is about 44032.9422024011. The cubic root of 1938899999 is about 1246.9579358020.

The spelling of 1938899999 in words is "one billion, nine hundred thirty-eight million, eight hundred ninety-nine thousand, nine hundred ninety-nine".