1605561020 has 24 divisors (see below), whose sum is σ = 3853346784. Its totient is φ = 550478016.

The previous prime is 1605560989. The next prime is 1605561029. The reversal of 1605561020 is 201655061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1605561029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5734007 + ... + 5734286.

It is an arithmetic number, because the mean of its divisors is an integer number (160556116).

Almost surely, 2^1605561020 is an apocalyptic number.

1605561020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1605561020 is an abundant number, since it is smaller than the sum of its proper divisors (2247785764).

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

1605561020 is a wasteful number, since it uses less digits than its factorization.

1605561020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11468309 (or 11468307 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 1605561020 is about 40069.4524544571. The cubic root of 1605561020 is about 1170.9605718564.

The spelling of 1605561020 in words is "one billion, six hundred five million, five hundred sixty-one thousand, twenty".