1605604420 has 24 divisors (see below), whose sum is σ = 3853450944. Its totient is φ = 550492896.

The previous prime is 1605604409. The next prime is 1605604463. The reversal of 1605604420 is 244065061.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5734162 + ... + 5734441.

It is an arithmetic number, because the mean of its divisors is an integer number (160560456).

Almost surely, 2^1605604420 is an apocalyptic number.

1605604420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1605604420 is an abundant number, since it is smaller than the sum of its proper divisors (2247846524).

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

1605604420 is a wasteful number, since it uses less digits than its factorization.

1605604420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11468619 (or 11468617 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 1605604420 is about 40069.9940104812. The cubic root of 1605604420 is about 1170.9711225259.

Adding to 1605604420 its reverse (244065061), we get a palindrome (1849669481).

The spelling of 1605604420 in words is "one billion, six hundred five million, six hundred four thousand, four hundred twenty".