1605605320 has 128 divisors (see below), whose sum is σ = 4146785280. Its totient is φ = 554112000.

The previous prime is 1605605249. The next prime is 1605605381. The reversal of 1605605320 is 235065061.

It is a super-2 number, since 2×1605605320² = 5155936887224604800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 721810 + ... + 724030.

It is an arithmetic number, because the mean of its divisors is an integer number (32396760).

Almost surely, 2^1605605320 is an apocalyptic number.

1605605320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1605605320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2073392640).

1605605320 is an abundant number, since it is smaller than the sum of its proper divisors (2541179960).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1605605320 is a wasteful number, since it uses less digits than its factorization.

1605605320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2327 (or 2323 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 1605605320 is about 40070.0052408282. The cubic root of 1605605320 is about 1170.9713413165.

The spelling of 1605605320 in words is "one billion, six hundred five million, six hundred five thousand, three hundred twenty".