1605795840 has 480 divisors, whose sum is σ = 6327928530. Its totient is φ = 389283840.

The previous prime is 1605795839. The next prime is 1605795847. The reversal of 1605795840 is 485975061.

1605795840 is a `hidden beast` number, since 1 + 60 + 5 + 7 + 9 + 584 + 0 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1445216256 + 160579584 = 38016^2 + 12672^2 .

It is a tau number, because it is divible by the number of its divisors (480).

It is a super-2 number, since 2×1605795840² = 5157160559522611200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1605795847) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 145981435 + ... + 145981445.

Almost surely, 2^1605795840 is an apocalyptic number.

1605795840 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 1605795840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3163964265).

1605795840 is an abundant number, since it is smaller than the sum of its proper divisors (4722132690).

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

1605795840 is an frugal number, since it uses more digits than its factorization.

1605795840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69 (or 21 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The square root of 1605795840 is about 40072.3825096537. The cubic root of 1605795840 is about 1171.0176550305.

The spelling of 1605795840 in words is "one billion, six hundred five million, seven hundred ninety-five thousand, eight hundred forty".