20809343437960 has 512 divisors, whose sum is σ = 62956247777280. Its totient is φ = 5996349849600.

The previous prime is 20809343437957. The next prime is 20809343437979. The reversal of 20809343437960 is 6973434390802.

It is a junction number, because it is equal to n+sod(n) for n = 20809343437895 and 20809343437904.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1882000752 + ... + 1882011808.

It is an arithmetic number, because the mean of its divisors is an integer number (122961421440).

Almost surely, 2^{20809343437960} is an apocalyptic number.

20809343437960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20809343437960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31478123888640).

20809343437960 is an abundant number, since it is smaller than the sum of its proper divisors (42146904339320).

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

20809343437960 is a wasteful number, since it uses less digits than its factorization.

20809343437960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11997 (or 11993 counting only the distinct ones).

The product of its (nonzero) digits is 23514624, while the sum is 58.

The spelling of 20809343437960 in words is "twenty trillion, eight hundred nine billion, three hundred forty-three million, four hundred thirty-seven thousand, nine hundred sixty".