20109523409 has 2 divisors, whose sum is σ = 20109523410. Its totient is φ = 20109523408.

The previous prime is 20109523381. The next prime is 20109523457. The reversal of 20109523409 is 90432590102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14005539025 + 6103984384 = 118345^2 + 78128^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20109523409 is a prime.

It is not a weakly prime, because it can be changed into another prime (20109543409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10054761704 + 10054761705.

It is an arithmetic number, because the mean of its divisors is an integer number (10054761705).

Almost surely, 2^20109523409 is an apocalyptic number.

It is an amenable number.

20109523409 is a deficient number, since it is larger than the sum of its proper divisors (1).

20109523409 is an equidigital number, since it uses as much as digits as its factorization.

20109523409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 35.

The spelling of 20109523409 in words is "twenty billion, one hundred nine million, five hundred twenty-three thousand, four hundred nine".