1680725565 has 32 divisors (see below), whose sum is σ = 3000412800. Its totient is φ = 892650240.

The previous prime is 1680725549. The next prime is 1680725567. The reversal of 1680725565 is 5655270861.

1680725565 is a `hidden beast` number, since 1 + 6 + 80 + 7 + 2 + 5 + 565 = 666.

It is not a de Polignac number, because 1680725565 - 2⁴ = 1680725549 is a prime.

It is a super-3 number, since 3×1680725565³ (a number of 29 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1680725565.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680725567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6706 + ... + 58364.

It is an arithmetic number, because the mean of its divisors is an integer number (93762900).

Almost surely, 2^1680725565 is an apocalyptic number.

1680725565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1680725565 is a deficient number, since it is larger than the sum of its proper divisors (1319687235).

1680725565 is a wasteful number, since it uses less digits than its factorization.

1680725565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51914 (or 51908 counting only the distinct ones).

The product of its (nonzero) digits is 504000, while the sum is 45.

The square root of 1680725565 is about 40996.6530951003. The cubic root of 1680725565 is about 1188.9555048788.

The spelling of 1680725565 in words is "one billion, six hundred eighty million, seven hundred twenty-five thousand, five hundred sixty-five".