20516525137 has 4 divisors (see below), whose sum is σ = 20529771700. Its totient is φ = 20503278576.

The previous prime is 20516525129. The next prime is 20516525143. The reversal of 20516525137 is 73152561502.

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 2797986816 + 17718538321 = 52896^2 + 133111^2 .

It is a cyclic number.

It is not a de Polignac number, because 20516525137 - 2³ = 20516525129 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20516525096 and 20516525105.

It is not an unprimeable number, because it can be changed into a prime (20516525537) 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, 6620958 + ... + 6624055.

It is an arithmetic number, because the mean of its divisors is an integer number (5132442925).

Almost surely, 2^20516525137 is an apocalyptic number.

It is an amenable number.

20516525137 is a deficient number, since it is larger than the sum of its proper divisors (13246563).

20516525137 is a wasteful number, since it uses less digits than its factorization.

20516525137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13246562.

The product of its (nonzero) digits is 63000, while the sum is 37.

The spelling of 20516525137 in words is "twenty billion, five hundred sixteen million, five hundred twenty-five thousand, one hundred thirty-seven".