20556555500 has 96 divisors (see below), whose sum is σ = 48413671488. Its totient is φ = 7579968000.

The previous prime is 20556555433. The next prime is 20556555511. The reversal of 20556555500 is 555565502.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6309872 + ... + 6313128.

It is an arithmetic number, because the mean of its divisors is an integer number (504309078).

Almost surely, 2^20556555500 is an apocalyptic number.

20556555500 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 20556555500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24206835744).

20556555500 is an abundant number, since it is smaller than the sum of its proper divisors (27857115988).

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

20556555500 is a wasteful number, since it uses less digits than its factorization.

20556555500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4260 (or 4248 counting only the distinct ones).

The product of its (nonzero) digits is 187500, while the sum is 38.

The spelling of 20556555500 in words is "twenty billion, five hundred fifty-six million, five hundred fifty-five thousand, five hundred".