1605006505 has 4 divisors (see below), whose sum is σ = 1926007812. Its totient is φ = 1284005200.

The previous prime is 1605006467. The next prime is 1605006517. The reversal of 1605006505 is 5056005061.

1605006505 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 598340521 + 1006665984 = 24461^2 + 31728^2 .

It is not a de Polignac number, because 1605006505 - 2⁹ = 1605005993 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, 160500646 + ... + 160500655.

It is an arithmetic number, because the mean of its divisors is an integer number (481501953).

Almost surely, 2^1605006505 is an apocalyptic number.

It is an amenable number.

1605006505 is a deficient number, since it is larger than the sum of its proper divisors (321001307).

1605006505 is an equidigital number, since it uses as much as digits as its factorization.

1605006505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321001306.

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 1605006505 is about 40062.5324336842. The cubic root of 1605006505 is about 1170.8257508687.

The spelling of 1605006505 in words is "one billion, six hundred five million, six thousand, five hundred five".