20557055520 has 432 divisors, whose sum is σ = 76178164608. Its totient is φ = 5044838400.

The previous prime is 20557055459. The next prime is 20557055521. The reversal of 20557055520 is 2555075502.

20557055520 is a `hidden beast` number, since 2 + 0 + 557 + 0 + 55 + 52 + 0 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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 (20557055521) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 19558995 + ... + 19560045.

It is an arithmetic number, because the mean of its divisors is an integer number (176338344).

Almost surely, 2^20557055520 is an apocalyptic number.

20557055520 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 20557055520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38089082304).

20557055520 is an abundant number, since it is smaller than the sum of its proper divisors (55621109088).

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

20557055520 is a wasteful number, since it uses less digits than its factorization.

20557055520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1153 (or 1125 counting only the distinct ones).

The product of its (nonzero) digits is 87500, while the sum is 36.

The spelling of 20557055520 in words is "twenty billion, five hundred fifty-seven million, fifty-five thousand, five hundred twenty".