20268821609 has 2 divisors, whose sum is σ = 20268821610. Its totient is φ = 20268821608.

The previous prime is 20268821603. The next prime is 20268821627. The reversal of 20268821609 is 90612886202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13018810000 + 7250011609 = 114100^2 + 85147^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20268821609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20268821609.

It is not a weakly prime, because it can be changed into another prime (20268821603) 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, 10134410804 + 10134410805.

It is an arithmetic number, because the mean of its divisors is an integer number (10134410805).

Almost surely, 2^20268821609 is an apocalyptic number.

It is an amenable number.

20268821609 is a deficient number, since it is larger than the sum of its proper divisors (1).

20268821609 is an equidigital number, since it uses as much as digits as its factorization.

20268821609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 165888, while the sum is 44.

The spelling of 20268821609 in words is "twenty billion, two hundred sixty-eight million, eight hundred twenty-one thousand, six hundred nine".