20520553608 has 80 divisors (see below), whose sum is σ = 57605377500. Its totient is φ = 6824853504.

The previous prime is 20520553601. The next prime is 20520553619. The reversal of 20520553608 is 80635502502.

It is a happy number.

20520553608 is a `hidden beast` number, since 20 + 5 + 20 + 5 + 5 + 3 + 608 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20379846564 + 140707044 = 142758^2 + 11862^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (20520553601) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 255688 + ... + 326216.

Almost surely, 2^20520553608 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 20520553608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28802688750).

20520553608 is an abundant number, since it is smaller than the sum of its proper divisors (37084823892).

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

20520553608 is a wasteful number, since it uses less digits than its factorization.

20520553608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70996 (or 70983 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The spelling of 20520553608 in words is "twenty billion, five hundred twenty million, five hundred fifty-three thousand, six hundred eight".