20936499173 has 4 divisors (see below), whose sum is σ = 21502350540. Its totient is φ = 20370647808.

The previous prime is 20936499169. The next prime is 20936499193. The reversal of 20936499173 is 37199463902.

It is a happy number.

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 16848559204 + 4087939969 = 129802^2 + 63937^2 .

It is a cyclic number.

It is not a de Polignac number, because 20936499173 - 2² = 20936499169 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 (20936499193) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 282925628 + ... + 282925701.

It is an arithmetic number, because the mean of its divisors is an integer number (5375587635).

Almost surely, 2^20936499173 is an apocalyptic number.

It is an amenable number.

20936499173 is a deficient number, since it is larger than the sum of its proper divisors (565851367).

20936499173 is an equidigital number, since it uses as much as digits as its factorization.

20936499173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565851366.

The product of its (nonzero) digits is 2204496, while the sum is 53.

The spelling of 20936499173 in words is "twenty billion, nine hundred thirty-six million, four hundred ninety-nine thousand, one hundred seventy-three".