20320121989 has 2 divisors, whose sum is σ = 20320121990. Its totient is φ = 20320121988.

The previous prime is 20320121963. The next prime is 20320122023. The reversal of 20320121989 is 98912102302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19783829025 + 536292964 = 140655^2 + 23158^2 .

It is a cyclic number.

It is not a de Polignac number, because 20320121989 - 2¹³ = 20320113797 is a prime.

It is a super-2 number, since 2×20320121989² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20323121989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10160060994 + 10160060995.

It is an arithmetic number, because the mean of its divisors is an integer number (10160060995).

Almost surely, 2^20320121989 is an apocalyptic number.

It is an amenable number.

20320121989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20320121989 is an equidigital number, since it uses as much as digits as its factorization.

20320121989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 37.

The spelling of 20320121989 in words is "twenty billion, three hundred twenty million, one hundred twenty-one thousand, nine hundred eighty-nine".