20508860137 has 4 divisors (see below), whose sum is σ = 20514186820. Its totient is φ = 20503533456.

The previous prime is 20508860101. The next prime is 20508860173. The reversal of 20508860137 is 73106880502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73106880502 = 2 ⋅36553440251.

It is an interprime number because it is at equal distance from previous prime (20508860101) and next prime (20508860173).

It can be written as a sum of positive squares in 2 ways, for example, as 20124543321 + 384316816 = 141861^2 + 19604^2 .

It is a cyclic number.

It is not a de Polignac number, because 20508860137 - 2¹⁵ = 20508827369 is a prime.

It is a super-2 number, since 2×20508860137² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20508860137.

It is not an unprimeable number, because it can be changed into a prime (20508860837) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2657562 + ... + 2665267.

It is an arithmetic number, because the mean of its divisors is an integer number (5128546705).

Almost surely, 2^20508860137 is an apocalyptic number.

It is an amenable number.

20508860137 is a deficient number, since it is larger than the sum of its proper divisors (5326683).

20508860137 is an equidigital number, since it uses as much as digits as its factorization.

20508860137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5326682.

The product of its (nonzero) digits is 80640, while the sum is 40.

It can be divided in two parts, 205088 and 60137, that added together give a square (265225 = 515²).

The spelling of 20508860137 in words is "twenty billion, five hundred eight million, eight hundred sixty thousand, one hundred thirty-seven".