804508921 has 2 divisors, whose sum is σ = 804508922. Its totient is φ = 804508920.

The previous prime is 804508909. The next prime is 804508933. The reversal of 804508921 is 129805408.

It is the 11580-th star number.

It is a balanced prime because it is at equal distance from previous prime (804508909) and next prime (804508933).

It can be written as a sum of positive squares in only one way, i.e., 434138896 + 370370025 = 20836^2 + 19245^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-804508921 is a prime.

It is not a weakly prime, because it can be changed into another prime (804508951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402254460 + 402254461.

It is an arithmetic number, because the mean of its divisors is an integer number (402254461).

Almost surely, 2^804508921 is an apocalyptic number.

It is an amenable number.

804508921 is a deficient number, since it is larger than the sum of its proper divisors (1).

804508921 is an equidigital number, since it uses as much as digits as its factorization.

804508921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 804508921 is about 28363.8664677438. The cubic root of 804508921 is about 930.0585468210.

The spelling of 804508921 in words is "eight hundred four million, five hundred eight thousand, nine hundred twenty-one".