20948819609 has 2 divisors, whose sum is σ = 20948819610. Its totient is φ = 20948819608.

The previous prime is 20948819603. The next prime is 20948819629. The reversal of 20948819609 is 90691884902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18156754009 + 2792065600 = 134747^2 + 52840^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20948819609 is a prime.

It is not a weakly prime, because it can be changed into another prime (20948819603) 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, 10474409804 + 10474409805.

It is an arithmetic number, because the mean of its divisors is an integer number (10474409805).

Almost surely, 2^20948819609 is an apocalyptic number.

It is an amenable number.

20948819609 is a deficient number, since it is larger than the sum of its proper divisors (1).

20948819609 is an equidigital number, since it uses as much as digits as its factorization.

20948819609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2239488, while the sum is 56.

The spelling of 20948819609 in words is "twenty billion, nine hundred forty-eight million, eight hundred nineteen thousand, six hundred nine".