61620755055561 has 16 divisors (see below), whose sum is σ = 98312315758720. Its totient is φ = 37920464649360.

The previous prime is 61620755055539. The next prime is 61620755055569. The reversal of 61620755055561 is 16555055702616.

61620755055561 is a `hidden beast` number, since 6 + 1 + 6 + 2 + 0 + 75 + 5 + 0 + 5 + 5 + 561 = 666.

It is not a de Polignac number, because 61620755055561 - 2¹⁴ = 61620755039177 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61620755055498 and 61620755055507.

It is not an unprimeable number, because it can be changed into a prime (61620755055569) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87778853005 + ... + 87778853706.

It is an arithmetic number, because the mean of its divisors is an integer number (6144519734920).

Almost surely, 2^{61620755055561} is an apocalyptic number.

It is an amenable number.

61620755055561 is a deficient number, since it is larger than the sum of its proper divisors (36691560703159).

61620755055561 is a wasteful number, since it uses less digits than its factorization.

61620755055561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175557706733 (or 175557706727 counting only the distinct ones).

The product of its (nonzero) digits is 9450000, while the sum is 54.

The spelling of 61620755055561 in words is "sixty-one trillion, six hundred twenty billion, seven hundred fifty-five million, fifty-five thousand, five hundred sixty-one".