1665505655 has 32 divisors (see below), whose sum is σ = 2243827008. Its totient is φ = 1176448000.

The previous prime is 1665505643. The next prime is 1665505663. The reversal of 1665505655 is 5565055661.

It is not a de Polignac number, because 1665505655 - 2⁸ = 1665505399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 291587 + ... + 297243.

It is an arithmetic number, because the mean of its divisors is an integer number (70119594).

Almost surely, 2^1665505655 is an apocalyptic number.

1665505655 is a deficient number, since it is larger than the sum of its proper divisors (578321353).

1665505655 is a wasteful number, since it uses less digits than its factorization.

1665505655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5827.

The product of its (nonzero) digits is 675000, while the sum is 44.

The square root of 1665505655 is about 40810.6071383409. The cubic root of 1665505655 is about 1185.3557312369.

The spelling of 1665505655 in words is "one billion, six hundred sixty-five million, five hundred five thousand, six hundred fifty-five".