20318989 has 2 divisors, whose sum is σ = 20318990. Its totient is φ = 20318988.

The previous prime is 20318971. The next prime is 20319007. The reversal of 20318989 is 98981302.

It is a balanced prime because it is at equal distance from previous prime (20318971) and next prime (20319007).

It can be written as a sum of positive squares in only one way, i.e., 16670889 + 3648100 = 4083^2 + 1910^2 .

It is a cyclic number.

It is not a de Polignac number, because 20318989 - 2⁹ = 20318477 is a prime.

It is a super-2 number, since 2×20318989² = 825722627964242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20318939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10159494 + 10159495.

It is an arithmetic number, because the mean of its divisors is an integer number (10159495).

Almost surely, 2^20318989 is an apocalyptic number.

It is an amenable number.

20318989 is a deficient number, since it is larger than the sum of its proper divisors (1).

20318989 is an equidigital number, since it uses as much as digits as its factorization.

20318989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 20318989 is about 4507.6589267601. The cubic root of 20318989 is about 272.8772722295.

The spelling of 20318989 in words is "twenty million, three hundred eighteen thousand, nine hundred eighty-nine".