20564613280 has 48 divisors (see below), whose sum is σ = 48659935464. Its totient is φ = 8212971520.

The previous prime is 20564613257. The next prime is 20564613287. The reversal of 20564613280 is 8231646502.

It can be written as a sum of positive squares in 4 ways, for example, as 17713480464 + 2851132816 = 133092^2 + 53396^2 .

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (20564613287) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2304 + ... + 202816.

Almost surely, 2^20564613280 is an apocalyptic number.

20564613280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20564613280 is an abundant number, since it is smaller than the sum of its proper divisors (28095322184).

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

20564613280 is a wasteful number, since it uses less digits than its factorization.

20564613280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201169 (or 201161 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 37.

The spelling of 20564613280 in words is "twenty billion, five hundred sixty-four million, six hundred thirteen thousand, two hundred eighty".