20345665536 has 360 divisors, whose sum is σ = 70721010360. Its totient is φ = 5810724864.

The previous prime is 20345665511. The next prime is 20345665541. The reversal of 20345665536 is 63556654302.

20345665536 is a `hidden beast` number, since 2 + 0 + 3 + 4 + 56 + 65 + 536 = 666.

It is a super-2 number, since 2×20345665536² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20345665491 and 20345665500.

It is a congruent 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 29 ways as a sum of consecutive naturals, for example, 8127261 + ... + 8129763.

It is an arithmetic number, because the mean of its divisors is an integer number (196447251).

Almost surely, 2^20345665536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20345665536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35360505180).

20345665536 is an abundant number, since it is smaller than the sum of its proper divisors (50375344824).

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

20345665536 is an equidigital number, since it uses as much as digits as its factorization.

20345665536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2551 (or 2515 counting only the distinct ones).

The product of its (nonzero) digits is 1944000, while the sum is 45.

The spelling of 20345665536 in words is "twenty billion, three hundred forty-five million, six hundred sixty-five thousand, five hundred thirty-six".