19983989 has 2 divisors, whose sum is σ = 19983990. Its totient is φ = 19983988.

The previous prime is 19983983. The next prime is 19984001. The reversal of 19983989 is 98938991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15288100 + 4695889 = 3910^2 + 2167^2 .

It is a cyclic number.

It is not a de Polignac number, because 19983989 - 2⁴ = 19983973 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19983983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9991994 + 9991995.

It is an arithmetic number, because the mean of its divisors is an integer number (9991995).

Almost surely, 2^19983989 is an apocalyptic number.

It is an amenable number.

19983989 is a deficient number, since it is larger than the sum of its proper divisors (1).

19983989 is an equidigital number, since it uses as much as digits as its factorization.

19983989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1259712, while the sum is 56.

The square root of 19983989 is about 4470.3455123737. The cubic root of 19983989 is about 271.3693080877.

The spelling of 19983989 in words is "nineteen million, nine hundred eighty-three thousand, nine hundred eighty-nine".