1605601620 has 108 divisors (see below), whose sum is σ = 5665511124. Its totient is φ = 366992640.

The previous prime is 1605601619. The next prime is 1605601637. The reversal of 1605601620 is 261065061.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 425266884 + 1180334736 = 20622^2 + 34356^2 .

It is a congruent number.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 82201 + ... + 99840.

Almost surely, 2^1605601620 is an apocalyptic number.

1605601620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1605601620 is an abundant number, since it is smaller than the sum of its proper divisors (4059909504).

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

1605601620 is a wasteful number, since it uses less digits than its factorization.

1605601620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182070 (or 182058 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 1605601620 is about 40069.9590716038. The cubic root of 1605601620 is about 1170.9704418433.

Adding to 1605601620 its reverse (261065061), we get a palindrome (1866666681).

The spelling of 1605601620 in words is "one billion, six hundred five million, six hundred one thousand, six hundred twenty".