1605120020 has 24 divisors (see below), whose sum is σ = 3852288384. Its totient is φ = 550326816.

The previous prime is 1605120017. The next prime is 1605120037. The reversal of 1605120020 is 200215061.

It is a congruent number.

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, 5732432 + ... + 5732711.

It is an arithmetic number, because the mean of its divisors is an integer number (160512016).

Almost surely, 2^1605120020 is an apocalyptic number.

1605120020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1605120020 is an abundant number, since it is smaller than the sum of its proper divisors (2247168364).

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

1605120020 is a wasteful number, since it uses less digits than its factorization.

1605120020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11465159 (or 11465157 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 1605120020 is about 40063.9491313575. The cubic root of 1605120020 is about 1170.8533526576.

Adding to 1605120020 its reverse (200215061), we get a palindrome (1805335081).

The spelling of 1605120020 in words is "one billion, six hundred five million, one hundred twenty thousand, twenty".