16555106665 has 4 divisors (see below), whose sum is σ = 19866128004. Its totient is φ = 13244085328.

The previous prime is 16555106639. The next prime is 16555106671. The reversal of 16555106665 is 56660155561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56660155561 = 79 ⋅717217159.

It can be written as a sum of positive squares in 2 ways, for example, as 11798521641 + 4756585024 = 108621^2 + 68968^2 .

It is a cyclic number.

It is not a de Polignac number, because 16555106665 - 2²⁷ = 16420888937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1655510662 + ... + 1655510671.

It is an arithmetic number, because the mean of its divisors is an integer number (4966532001).

Almost surely, 2^16555106665 is an apocalyptic number.

It is an amenable number.

16555106665 is a deficient number, since it is larger than the sum of its proper divisors (3311021339).

16555106665 is an equidigital number, since it uses as much as digits as its factorization.

16555106665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3311021338.

The product of its (nonzero) digits is 810000, while the sum is 46.

The spelling of 16555106665 in words is "sixteen billion, five hundred fifty-five million, one hundred six thousand, six hundred sixty-five".