2001665655 has 64 divisors (see below), whose sum is σ = 3892492800. Its totient is φ = 967887360.

The previous prime is 2001665647. The next prime is 2001665671. The reversal of 2001665655 is 5565661002.

It is a happy number.

It is not a de Polignac number, because 2001665655 - 2³ = 2001665647 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 620607 + ... + 623823.

It is an arithmetic number, because the mean of its divisors is an integer number (60820200).

Almost surely, 2^2001665655 is an apocalyptic number.

2001665655 is a deficient number, since it is larger than the sum of its proper divisors (1890827145).

2001665655 is a wasteful number, since it uses less digits than its factorization.

2001665655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3661 (or 3655 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 2001665655 is about 44739.9782632938. The cubic root of 2001665655 is about 1260.2707184744.

The spelling of 2001665655 in words is "two billion, one million, six hundred sixty-five thousand, six hundred fifty-five".