1605744725 has 12 divisors (see below), whose sum is σ = 2144287236. Its totient is φ = 1185780480.

The previous prime is 1605744667. The next prime is 1605744779. The reversal of 1605744725 is 5274475061.

It can be written as a sum of positive squares in 6 ways, for example, as 650811121 + 954933604 = 25511^2 + 30902^2 .

It is not a de Polignac number, because 1605744725 - 2¹⁰ = 1605743701 is a prime.

It is a super-2 number, since 2×1605744725² = 5156832243730651250, which contains 22 as substring.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2470052 + ... + 2470701.

It is an arithmetic number, because the mean of its divisors is an integer number (178690603).

Almost surely, 2^1605744725 is an apocalyptic number.

It is an amenable number.

1605744725 is a deficient number, since it is larger than the sum of its proper divisors (538542511).

1605744725 is a wasteful number, since it uses less digits than its factorization.

1605744725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4940776 (or 4940771 counting only the distinct ones).

The product of its (nonzero) digits is 235200, while the sum is 41.

The square root of 1605744725 is about 40071.7447211873. The cubic root of 1605744725 is about 1171.0052297892.

The spelling of 1605744725 in words is "one billion, six hundred five million, seven hundred forty-four thousand, seven hundred twenty-five".