561557366122172 has 24 divisors (see below), whose sum is σ = 1124109519492960. Its totient is φ = 240454273927680.

The previous prime is 561557366122117. The next prime is 561557366122189. The reversal of 561557366122172 is 271221663755165.

It is a super-2 number, since 2×561557366122172² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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, 8881996829 + ... + 8882060052.

It is an arithmetic number, because the mean of its divisors is an integer number (46837896645540).

Almost surely, 2^{561557366122172} is an apocalyptic number.

It is an amenable number.

561557366122172 is an abundant number, since it is smaller than the sum of its proper divisors (562552153370788).

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

561557366122172 is a wasteful number, since it uses less digits than its factorization.

561557366122172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17764058021 (or 17764058019 counting only the distinct ones).

The product of its digits is 31752000, while the sum is 59.

The spelling of 561557366122172 in words is "five hundred sixty-one trillion, five hundred fifty-seven billion, three hundred sixty-six million, one hundred twenty-two thousand, one hundred seventy-two".