20950887989 has 2 divisors, whose sum is σ = 20950887990. Its totient is φ = 20950887988.

The previous prime is 20950887901. The next prime is 20950888001. The reversal of 20950887989 is 98978805902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17039386225 + 3911501764 = 130535^2 + 62542^2 .

It is a cyclic number.

It is not a de Polignac number, because 20950887989 - 2³² = 16655920693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20950887389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10475443994 + 10475443995.

It is an arithmetic number, because the mean of its divisors is an integer number (10475443995).

Almost surely, 2^20950887989 is an apocalyptic number.

It is an amenable number.

20950887989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20950887989 is an equidigital number, since it uses as much as digits as its factorization.

20950887989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26127360, while the sum is 65.

The spelling of 20950887989 in words is "twenty billion, nine hundred fifty million, eight hundred eighty-seven thousand, nine hundred eighty-nine".