680290921 has 4 divisors (see below), whose sum is σ = 720308052. Its totient is φ = 640273792.

The previous prime is 680290879. The next prime is 680290931. The reversal of 680290921 is 129092086.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 377913600 + 302377321 = 19440^2 + 17389^2 .

It is a cyclic number.

It is not a de Polignac number, because 680290921 - 2¹⁷ = 680159849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (680290931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20008540 + ... + 20008573.

It is an arithmetic number, because the mean of its divisors is an integer number (180077013).

Almost surely, 2^680290921 is an apocalyptic number.

It is an amenable number.

680290921 is a deficient number, since it is larger than the sum of its proper divisors (40017131).

680290921 is a wasteful number, since it uses less digits than its factorization.

680290921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40017130.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 680290921 is about 26082.3871798576. The cubic root of 680290921 is about 879.4913214624.

The spelling of 680290921 in words is "six hundred eighty million, two hundred ninety thousand, nine hundred twenty-one".