20561564464122 has 16 divisors (see below), whose sum is σ = 44861595194592. Its totient is φ = 6230777110320.

The previous prime is 20561564464121. The next prime is 20561564464183. The reversal of 20561564464122 is 22146446516502.

It is not an unprimeable number, because it can be changed into a prime (20561564464121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155769427693 + ... + 155769427824.

It is an arithmetic number, because the mean of its divisors is an integer number (2803849699662).

Almost surely, 2^{20561564464122} is an apocalyptic number.

20561564464122 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

20561564464122 is an abundant number, since it is smaller than the sum of its proper divisors (24300030730470).

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

20561564464122 is a wasteful number, since it uses less digits than its factorization.

20561564464122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311538855533.

The product of its (nonzero) digits is 2764800, while the sum is 48.

The spelling of 20561564464122 in words is "twenty trillion, five hundred sixty-one billion, five hundred sixty-four million, four hundred sixty-four thousand, one hundred twenty-two".