20809518260 has 48 divisors (see below), whose sum is σ = 44613147600. Its totient is φ = 8150498304.

The previous prime is 20809518239. The next prime is 20809518263. The reversal of 20809518260 is 6281590802.

It can be written as a sum of positive squares in 8 ways, for example, as 1757789476 + 19051728784 = 41926^2 + 138028^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20809518263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 520256 + ... + 558824.

It is an arithmetic number, because the mean of its divisors is an integer number (929440575).

Almost surely, 2^20809518260 is an apocalyptic number.

20809518260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20809518260 is an abundant number, since it is smaller than the sum of its proper divisors (23803629340).

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

20809518260 is a wasteful number, since it uses less digits than its factorization.

20809518260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39140 (or 39138 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 41.

The spelling of 20809518260 in words is "twenty billion, eight hundred nine million, five hundred eighteen thousand, two hundred sixty".