1680624565 has 4 divisors (see below), whose sum is σ = 2016749484. Its totient is φ = 1344499648.

The previous prime is 1680624557. The next prime is 1680624571. The reversal of 1680624565 is 5654260861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5654260861 = 61 ⋅92692801.

It can be written as a sum of positive squares in 2 ways, for example, as 705061809 + 975562756 = 26553^2 + 31234^2 .

It is a cyclic number.

It is not a de Polignac number, because 1680624565 - 2³ = 1680624557 is a prime.

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 3 ways as a sum of consecutive naturals, for example, 168062452 + ... + 168062461.

It is an arithmetic number, because the mean of its divisors is an integer number (504187371).

Almost surely, 2^1680624565 is an apocalyptic number.

It is an amenable number.

1680624565 is a deficient number, since it is larger than the sum of its proper divisors (336124919).

1680624565 is an equidigital number, since it uses as much as digits as its factorization.

1680624565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336124918.

The product of its (nonzero) digits is 345600, while the sum is 43.

The square root of 1680624565 is about 40995.4212687222. The cubic root of 1680624565 is about 1188.9316883966.

The spelling of 1680624565 in words is "one billion, six hundred eighty million, six hundred twenty-four thousand, five hundred sixty-five".