1605805725 has 24 divisors (see below), whose sum is σ = 2672533312. Its totient is φ = 850752000.

The previous prime is 1605805711. The next prime is 1605805759. The reversal of 1605805725 is 5275085061.

It is not a de Polignac number, because 1605805725 - 2⁸ = 1605805469 is a prime.

It is a super-2 number, since 2×1605805725² = 5157224052885551250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 59572 + ... + 82221.

Almost surely, 2^1605805725 is an apocalyptic number.

1605805725 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1605805725 is a deficient number, since it is larger than the sum of its proper divisors (1066727587).

1605805725 is a wasteful number, since it uses less digits than its factorization.

1605805725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141957 (or 141952 counting only the distinct ones).

The product of its (nonzero) digits is 84000, while the sum is 39.

The square root of 1605805725 is about 40072.5058487737. The cubic root of 1605805725 is about 1171.0200578859.

The spelling of 1605805725 in words is "one billion, six hundred five million, eight hundred five thousand, seven hundred twenty-five".