20505506560 has 288 divisors, whose sum is σ = 62903135232. Its totient is φ = 6217482240.

The previous prime is 20505506551. The next prime is 20505506611. The reversal of 20505506560 is 6560550502.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3643909 + ... + 3649531.

It is an arithmetic number, because the mean of its divisors is an integer number (218413664).

Almost surely, 2^20505506560 is an apocalyptic number.

20505506560 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 20505506560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31451567616).

20505506560 is an abundant number, since it is smaller than the sum of its proper divisors (42397628672).

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

20505506560 is a wasteful number, since it uses less digits than its factorization.

20505506560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5699 (or 5685 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 34.

The spelling of 20505506560 in words is "twenty billion, five hundred five million, five hundred six thousand, five hundred sixty".