1605745920 has 144 divisors (see below), whose sum is σ = 5351617152. Its totient is φ = 409559040.

The previous prime is 1605745903. The next prime is 1605745927. The reversal of 1605745920 is 295475061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1605745927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79230 + ... + 97410.

It is an arithmetic number, because the mean of its divisors is an integer number (37164008).

Almost surely, 2^1605745920 is an apocalyptic number.

1605745920 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 1605745920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2675808576).

1605745920 is an abundant number, since it is smaller than the sum of its proper divisors (3745871232).

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

1605745920 is a wasteful number, since it uses less digits than its factorization.

1605745920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18228 (or 18214 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 39.

The square root of 1605745920 is about 40071.7596319403. The cubic root of 1605745920 is about 1171.0055202776.

The spelling of 1605745920 in words is "one billion, six hundred five million, seven hundred forty-five thousand, nine hundred twenty".