20665325513 has 12 divisors (see below), whose sum is σ = 24060613140. Its totient is φ = 17697399552.

The previous prime is 20665325497. The next prime is 20665325537. The reversal of 20665325513 is 31552356602.

It can be written as a sum of positive squares in 2 ways, for example, as 8346101449 + 12319224064 = 91357^2 + 110992^2 .

It is not a de Polignac number, because 20665325513 - 2⁴ = 20665325497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20665321513) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 131456 + ... + 242097.

It is an arithmetic number, because the mean of its divisors is an integer number (2005051095).

Almost surely, 2^20665325513 is an apocalyptic number.

It is an amenable number.

20665325513 is a deficient number, since it is larger than the sum of its proper divisors (3395287627).

20665325513 is a wasteful number, since it uses less digits than its factorization.

20665325513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 374696 (or 374689 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 38.

The spelling of 20665325513 in words is "twenty billion, six hundred sixty-five million, three hundred twenty-five thousand, five hundred thirteen".