20396447989 has 2 divisors, whose sum is σ = 20396447990. Its totient is φ = 20396447988.

The previous prime is 20396447947. The next prime is 20396448011. The reversal of 20396447989 is 98974469302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14069518225 + 6326929764 = 118615^2 + 79542^2 .

It is a cyclic number.

It is not a de Polignac number, because 20396447989 - 2¹³ = 20396439797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20396444989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10198223994 + 10198223995.

It is an arithmetic number, because the mean of its divisors is an integer number (10198223995).

Almost surely, 2^20396447989 is an apocalyptic number.

It is an amenable number.

20396447989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20396447989 is an equidigital number, since it uses as much as digits as its factorization.

20396447989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23514624, while the sum is 61.

The spelling of 20396447989 in words is "twenty billion, three hundred ninety-six million, four hundred forty-seven thousand, nine hundred eighty-nine".