1680765621 has 8 divisors (see below), whose sum is σ = 2257143840. Its totient is φ = 1112448912.

The previous prime is 1680765617. The next prime is 1680765629. The reversal of 1680765621 is 1265670861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1680765621 - 2² = 1680765617 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680765629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2014890 + ... + 2015723.

It is an arithmetic number, because the mean of its divisors is an integer number (282142980).

Almost surely, 2^1680765621 is an apocalyptic number.

It is an amenable number.

1680765621 is a deficient number, since it is larger than the sum of its proper divisors (576378219).

1680765621 is a wasteful number, since it uses less digits than its factorization.

1680765621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4030755.

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 1680765621 is about 40997.1416198739. The cubic root of 1680765621 is about 1188.9649500899.

It can be divided in two parts, 16807 and 65621, that added together give a palindrome (82428).

The spelling of 1680765621 in words is "one billion, six hundred eighty million, seven hundred sixty-five thousand, six hundred twenty-one".