20828966993 has 4 divisors (see below), whose sum is σ = 21063000420. Its totient is φ = 20594933568.

The previous prime is 20828966971. The next prime is 20828967023. The reversal of 20828966993 is 39966982802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1691841424 + 19137125569 = 41132^2 + 138337^2 .

It is a cyclic number.

It is not a de Polignac number, because 20828966993 - 2¹² = 20828962897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20828960993) 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 in 3 ways as a sum of consecutive naturals, for example, 117016580 + ... + 117016757.

It is an arithmetic number, because the mean of its divisors is an integer number (5265750105).

Almost surely, 2^20828966993 is an apocalyptic number.

It is an amenable number.

20828966993 is a deficient number, since it is larger than the sum of its proper divisors (234033427).

20828966993 is an equidigital number, since it uses as much as digits as its factorization.

20828966993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234033426.

The product of its (nonzero) digits is 20155392, while the sum is 62.

The spelling of 20828966993 in words is "twenty billion, eight hundred twenty-eight million, nine hundred sixty-six thousand, nine hundred ninety-three".