16220505561 has 64 divisors (see below), whose sum is σ = 24853678080. Its totient is φ = 9327467520.

The previous prime is 16220505551. The next prime is 16220505563. The reversal of 16220505561 is 16550502261.

It is not a de Polignac number, because 16220505561 - 2¹⁰ = 16220504537 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16220505563) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 25705716 + ... + 25706346.

It is an arithmetic number, because the mean of its divisors is an integer number (388338720).

Almost surely, 2^16220505561 is an apocalyptic number.

It is an amenable number.

16220505561 is a deficient number, since it is larger than the sum of its proper divisors (8633172519).

16220505561 is a wasteful number, since it uses less digits than its factorization.

16220505561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1086.

The product of its (nonzero) digits is 18000, while the sum is 33.

The spelling of 16220505561 in words is "sixteen billion, two hundred twenty million, five hundred five thousand, five hundred sixty-one".