20564522550 has 288 divisors, whose sum is σ = 65180265696. Its totient is φ = 4582656000.

The previous prime is 20564522519. The next prime is 20564522557. The reversal of 20564522550 is 5522546502.

20564522550 is a `hidden beast` number, since 2 + 0 + 5 + 645 + 2 + 2 + 5 + 5 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20564522557) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 20141040 + ... + 20142060.

It is an arithmetic number, because the mean of its divisors is an integer number (226320367).

Almost surely, 2^20564522550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20564522550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32590132848).

20564522550 is an abundant number, since it is smaller than the sum of its proper divisors (44615743146).

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

20564522550 is a wasteful number, since it uses less digits than its factorization.

20564522550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1376 (or 1368 counting only the distinct ones).

The product of its (nonzero) digits is 120000, while the sum is 36.

The spelling of 20564522550 in words is "twenty billion, five hundred sixty-four million, five hundred twenty-two thousand, five hundred fifty".