1999893989 has 2 divisors, whose sum is σ = 1999893990. Its totient is φ = 1999893988.

The previous prime is 1999893983. The next prime is 1999894007. The reversal of 1999893989 is 9893989991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1891380100 + 108513889 = 43490^2 + 10417^2 .

It is a cyclic number.

It is not a de Polignac number, because 1999893989 - 2⁸ = 1999893733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1999893983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999946994 + 999946995.

It is an arithmetic number, because the mean of its divisors is an integer number (999946995).

Almost surely, 2^1999893989 is an apocalyptic number.

It is an amenable number.

1999893989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999893989 is an equidigital number, since it uses as much as digits as its factorization.

1999893989 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 1999893989 is about 44720.1742952775. The cubic root of 1999893989 is about 1259.8987885865.

The spelling of 1999893989 in words is "one billion, nine hundred ninety-nine million, eight hundred ninety-three thousand, nine hundred eighty-nine".