20461561206560 has 24 divisors (see below), whose sum is σ = 48340438350876. Its totient is φ = 8184624482560.

The previous prime is 20461561206557. The next prime is 20461561206563. The reversal of 20461561206560 is 6560216516402.

It is an interprime number because it is at equal distance from previous prime (20461561206557) and next prime (20461561206563).

It can be written as a sum of positive squares in 2 ways, for example, as 20205780167056 + 255781039504 = 4495084^2 + 505748^2 .

It is a super-2 number, since 2×20461561206560² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20461561206563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63942378611 + ... + 63942378930.

Almost surely, 2^{20461561206560} is an apocalyptic number.

20461561206560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20461561206560 is an abundant number, since it is smaller than the sum of its proper divisors (27878877144316).

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

20461561206560 is a wasteful number, since it uses less digits than its factorization.

20461561206560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127884757556 (or 127884757548 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 44.

The spelling of 20461561206560 in words is "twenty trillion, four hundred sixty-one billion, five hundred sixty-one million, two hundred six thousand, five hundred sixty".