1605723540 has 24 divisors (see below), whose sum is σ = 4496026080. Its totient is φ = 428192928.

The previous prime is 1605723503. The next prime is 1605723551. The reversal of 1605723540 is 453275061.

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, 13380970 + ... + 13381089.

It is an arithmetic number, because the mean of its divisors is an integer number (187334420).

Almost surely, 2^1605723540 is an apocalyptic number.

1605723540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1605723540 is an abundant number, since it is smaller than the sum of its proper divisors (2890302540).

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

1605723540 is a wasteful number, since it uses less digits than its factorization.

1605723540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26762071 (or 26762069 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 33.

The square root of 1605723540 is about 40071.4803819375. The cubic root of 1605723540 is about 1171.0000799762. Note that the first 4 decimals are identical.

The spelling of 1605723540 in words is "one billion, six hundred five million, seven hundred twenty-three thousand, five hundred forty".