20512145513 has 4 divisors (see below), whose sum is σ = 20548579728. Its totient is φ = 20475711300.

The previous prime is 20512145491. The next prime is 20512145519. The reversal of 20512145513 is 31554121502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31554121502 = 2 ⋅15777060751.

It is a cyclic number.

It is not a de Polignac number, because 20512145513 - 2⁸ = 20512145257 is a prime.

It is a super-2 number, since 2×20512145513² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20512145519) 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, 18216263 + ... + 18217388.

It is an arithmetic number, because the mean of its divisors is an integer number (5137144932).

Almost surely, 2^20512145513 is an apocalyptic number.

It is an amenable number.

20512145513 is a deficient number, since it is larger than the sum of its proper divisors (36434215).

20512145513 is an equidigital number, since it uses as much as digits as its factorization.

20512145513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36434214.

The product of its (nonzero) digits is 6000, while the sum is 29.

The spelling of 20512145513 in words is "twenty billion, five hundred twelve million, one hundred forty-five thousand, five hundred thirteen".