1605320880 has 160 divisors (see below), whose sum is σ = 5498648064. Its totient is φ = 385363968.

The previous prime is 1605320879. The next prime is 1605320891. The reversal of 1605320880 is 880235061.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 85287 + ... + 102393.

Almost surely, 2^1605320880 is an apocalyptic number.

1605320880 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 1605320880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2749324032).

1605320880 is an abundant number, since it is smaller than the sum of its proper divisors (3893327184).

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

1605320880 is a wasteful number, since it uses less digits than its factorization.

1605320880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17163 (or 17157 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 1605320880 is about 40066.4557953408. The cubic root of 1605320880 is about 1170.9021896692.

The spelling of 1605320880 in words is "one billion, six hundred five million, three hundred twenty thousand, eight hundred eighty".