20659799999 has 4 divisors (see below), whose sum is σ = 20908713336. Its totient is φ = 20410886664.

The previous prime is 20659799987. The next prime is 20659800017. The reversal of 20659799999 is 99999795602.

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

It is a cyclic number.

It is not a de Polignac number, because 20659799999 - 2¹² = 20659795903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20659799969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124456544 + ... + 124456709.

It is an arithmetic number, because the mean of its divisors is an integer number (5227178334).

Almost surely, 2^20659799999 is an apocalyptic number.

20659799999 is a deficient number, since it is larger than the sum of its proper divisors (248913337).

20659799999 is an equidigital number, since it uses as much as digits as its factorization.

20659799999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248913336.

The product of its (nonzero) digits is 223205220, while the sum is 74.

The spelling of 20659799999 in words is "twenty billion, six hundred fifty-nine million, seven hundred ninety-nine thousand, nine hundred ninety-nine".