20109493 has 2 divisors, whose sum is σ = 20109494. Its totient is φ = 20109492.

The previous prime is 20109491. The next prime is 20109503. The reversal of 20109493 is 39490102.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15194404 + 4915089 = 3898^2 + 2217^2 .

It is a cyclic number.

It is not a de Polignac number, because 20109493 - 2¹ = 20109491 is a prime.

Together with 20109491, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20109491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10054746 + 10054747.

It is an arithmetic number, because the mean of its divisors is an integer number (10054747).

Almost surely, 2^20109493 is an apocalyptic number.

It is an amenable number.

20109493 is a deficient number, since it is larger than the sum of its proper divisors (1).

20109493 is an equidigital number, since it uses as much as digits as its factorization.

20109493 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 20109493 is about 4484.3609355180. The cubic root of 20109493 is about 271.9362099905.

Adding to 20109493 its reverse (39490102), we get a palindrome (59599595).

It can be divided in two parts, 20109 and 493, that added together give a palindrome (20602).

The spelling of 20109493 in words is "twenty million, one hundred nine thousand, four hundred ninety-three".