20021019989 has 2 divisors, whose sum is σ = 20021019990. Its totient is φ = 20021019988.

The previous prime is 20021019983. The next prime is 20021020027. The reversal of 20021019989 is 98991012002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19900744900 + 120275089 = 141070^2 + 10967^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021019989 - 2⁴ = 20021019973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021019983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010509994 + 10010509995.

It is an arithmetic number, because the mean of its divisors is an integer number (10010509995).

Almost surely, 2^20021019989 is an apocalyptic number.

It is an amenable number.

20021019989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021019989 is an equidigital number, since it uses as much as digits as its factorization.

20021019989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 41.

The spelling of 20021019989 in words is "twenty billion, twenty-one million, nineteen thousand, nine hundred eighty-nine".