20979229393 has 2 divisors, whose sum is σ = 20979229394. Its totient is φ = 20979229392.

The previous prime is 20979229351. The next prime is 20979229463. The reversal of 20979229393 is 39392297902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20467021969 + 512207424 = 143063^2 + 22632^2 .

It is a cyclic number.

It is not a de Polignac number, because 20979229393 - 2¹⁷ = 20979098321 is a prime.

It is not a weakly prime, because it can be changed into another prime (20979229303) 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, 10489614696 + 10489614697.

It is an arithmetic number, because the mean of its divisors is an integer number (10489614697).

Almost surely, 2^20979229393 is an apocalyptic number.

It is an amenable number.

20979229393 is a deficient number, since it is larger than the sum of its proper divisors (1).

20979229393 is an equidigital number, since it uses as much as digits as its factorization.

20979229393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3306744, while the sum is 55.

The spelling of 20979229393 in words is "twenty billion, nine hundred seventy-nine million, two hundred twenty-nine thousand, three hundred ninety-three".