2001655 has 4 divisors (see below), whose sum is σ = 2401992. Its totient is φ = 1601320.

The previous prime is 2001653. The next prime is 2001673. The reversal of 2001655 is 5561002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5561002 = 2 ⋅2780501.

It is not a de Polignac number, because 2001655 - 2¹ = 2001653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200161 + ... + 200170.

It is an arithmetic number, because the mean of its divisors is an integer number (600498).

2^2001655 is an apocalyptic number.

2001655 is a deficient number, since it is larger than the sum of its proper divisors (400337).

2001655 is an equidigital number, since it uses as much as digits as its factorization.

2001655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400336.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 2001655 is about 1414.7985722356. The cubic root of 2001655 is about 126.0268482302.

Adding to 2001655 its reverse (5561002), we get a palindrome (7562657).

The spelling of 2001655 in words is "two million, one thousand, six hundred fifty-five".