20512505 has 32 divisors (see below), whose sum is σ = 27941760. Its totient is φ = 14353920.

The previous prime is 20512501. The next prime is 20512511. The reversal of 20512505 is 50521502.

It is not a de Polignac number, because 20512505 - 2² = 20512501 is a prime.

It is a super-2 number, since 2×20512505² = 841525722750050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20512501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 114506 + ... + 114684.

It is an arithmetic number, because the mean of its divisors is an integer number (873180).

Almost surely, 2^20512505 is an apocalyptic number.

It is an amenable number.

20512505 is a deficient number, since it is larger than the sum of its proper divisors (7429255).

20512505 is a wasteful number, since it uses less digits than its factorization.

20512505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281.

The product of its (nonzero) digits is 500, while the sum is 20.

The square root of 20512505 is about 4529.0733047722. The cubic root of 20512505 is about 273.7408217491.

The spelling of 20512505 in words is "twenty million, five hundred twelve thousand, five hundred five".