1605201655 has 4 divisors (see below), whose sum is σ = 1926241992. Its totient is φ = 1284161320.

The previous prime is 1605201623. The next prime is 1605201667. The reversal of 1605201655 is 5561025061.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5561025061 = 6211 ⋅895351.

It is not a de Polignac number, because 1605201655 - 2⁵ = 1605201623 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 (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160520161 + ... + 160520170.

It is an arithmetic number, because the mean of its divisors is an integer number (481560498).

Almost surely, 2^1605201655 is an apocalyptic number.

1605201655 is a deficient number, since it is larger than the sum of its proper divisors (321040337).

1605201655 is an equidigital number, since it uses as much as digits as its factorization.

1605201655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321040336.

The product of its (nonzero) digits is 9000, while the sum is 31.

The square root of 1605201655 is about 40064.9679271056. The cubic root of 1605201655 is about 1170.8732018468.

The spelling of 1605201655 in words is "one billion, six hundred five million, two hundred one thousand, six hundred fifty-five".