20509666528512 has 72 divisors (see below), whose sum is σ = 62383569040576. Its totient is φ = 5859904720896.

The previous prime is 20509666528457. The next prime is 20509666528537. The reversal of 20509666528512 is 21582566690502.

It is a super-2 number, since 2×20509666528512² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1907515693 + ... + 1907526444.

Almost surely, 2^{20509666528512} is an apocalyptic number.

It is an amenable number.

20509666528512 is an abundant number, since it is smaller than the sum of its proper divisors (41873902512064).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20509666528512 is an equidigital number, since it uses as much as digits as its factorization.

20509666528512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3815042163 (or 3815042149 counting only the distinct ones).

The product of its (nonzero) digits is 15552000, while the sum is 57.

The spelling of 20509666528512 in words is "twenty trillion, five hundred nine billion, six hundred sixty-six million, five hundred twenty-eight thousand, five hundred twelve".