20381689 has 2 divisors, whose sum is σ = 20381690. Its totient is φ = 20381688.

The previous prime is 20381677. The next prime is 20381701. The reversal of 20381689 is 98618302.

It is a balanced prime because it is at equal distance from previous prime (20381677) and next prime (20381701).

It can be written as a sum of positive squares in only one way, i.e., 19289664 + 1092025 = 4392^2 + 1045^2 .

It is a cyclic number.

It is not a de Polignac number, because 20381689 - 2⁹ = 20381177 is a prime.

It is not a weakly prime, because it can be changed into another prime (20381659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10190844 + 10190845.

It is an arithmetic number, because the mean of its divisors is an integer number (10190845).

Almost surely, 2^20381689 is an apocalyptic number.

It is an amenable number.

20381689 is a deficient number, since it is larger than the sum of its proper divisors (1).

20381689 is an equidigital number, since it uses as much as digits as its factorization.

20381689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 20381689 is about 4514.6083994074. The cubic root of 20381689 is about 273.1576640744.

The spelling of 20381689 in words is "twenty million, three hundred eighty-one thousand, six hundred eighty-nine".