1605001005 has 24 divisors (see below), whose sum is σ = 2782935168. Its totient is φ = 855713376.

The previous prime is 1605001001. The next prime is 1605001007. The reversal of 1605001005 is 5001005061.

1605001005 is a `hidden beast` number, since 1 + 60 + 500 + 100 + 5 = 666.

It is not a de Polignac number, because 1605001005 - 2² = 1605001001 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1605001001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 249864 + ... + 256206.

It is an arithmetic number, because the mean of its divisors is an integer number (115955632).

Almost surely, 2^1605001005 is an apocalyptic number.

1605001005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1605001005 is a deficient number, since it is larger than the sum of its proper divisors (1177934163).

1605001005 is a wasteful number, since it uses less digits than its factorization.

1605001005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11977 (or 11974 counting only the distinct ones).

The product of its (nonzero) digits is 150, while the sum is 18.

The square root of 1605001005 is about 40062.4637909353. The cubic root of 1605001005 is about 1170.8244134808.

Adding to 1605001005 its reverse (5001005061), we get a palindrome (6606006066).

The spelling of 1605001005 in words is "one billion, six hundred five million, one thousand, five".