20109999989 has 2 divisors, whose sum is σ = 20109999990. Its totient is φ = 20109999988.

The previous prime is 20109999971. The next prime is 20110000003. The reversal of 20109999989 is 98999990102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12759509764 + 7350490225 = 112958^2 + 85735^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20109999989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20109992989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10054999994 + 10054999995.

It is an arithmetic number, because the mean of its divisors is an integer number (10054999995).

Almost surely, 2^20109999989 is an apocalyptic number.

It is an amenable number.

20109999989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20109999989 is an equidigital number, since it uses as much as digits as its factorization.

20109999989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8503056, while the sum is 65.

The spelling of 20109999989 in words is "twenty billion, one hundred nine million, nine hundred ninety-nine thousand, nine hundred eighty-nine".