1605728940 has 24 divisors (see below), whose sum is σ = 4496041200. Its totient is φ = 428194368.

The previous prime is 1605728899. The next prime is 1605728941. The reversal of 1605728940 is 498275061.

It is a junction number, because it is equal to n+sod(n) for n = 1605728892 and 1605728901.

It is not an unprimeable number, because it can be changed into a prime (1605728941) 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, 13381015 + ... + 13381134.

It is an arithmetic number, because the mean of its divisors is an integer number (187335050).

Almost surely, 2^1605728940 is an apocalyptic number.

1605728940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1605728940 is an abundant number, since it is smaller than the sum of its proper divisors (2890312260).

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

1605728940 is a wasteful number, since it uses less digits than its factorization.

1605728940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26762161 (or 26762159 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 1605728940 is about 40071.5477614729. The cubic root of 1605728940 is about 1171.0013926541.

The spelling of 1605728940 in words is "one billion, six hundred five million, seven hundred twenty-eight thousand, nine hundred forty".