20111021199989 has 2 divisors, whose sum is σ = 20111021199990. Its totient is φ = 20111021199988.

The previous prime is 20111021199977. The next prime is 20111021200031. The reversal of 20111021199989 is 98999112011102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18081630062500 + 2029391137489 = 4252250^2 + 1424567^2 .

It is a cyclic number.

It is not a de Polignac number, because 20111021199989 - 2¹⁶ = 20111021134453 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20111021199989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20111021199089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055510599994 + 10055510599995.

It is an arithmetic number, because the mean of its divisors is an integer number (10055510599995).

Almost surely, 2^{20111021199989} is an apocalyptic number.

It is an amenable number.

20111021199989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111021199989 is an equidigital number, since it uses as much as digits as its factorization.

20111021199989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 209952, while the sum is 53.

The spelling of 20111021199989 in words is "twenty trillion, one hundred eleven billion, twenty-one million, one hundred ninety-nine thousand, nine hundred eighty-nine".