804161621 has 2 divisors, whose sum is σ = 804161622. Its totient is φ = 804161620.

The previous prime is 804161573. The next prime is 804161623. The reversal of 804161621 is 126161408.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 673973521 + 130188100 = 25961^2 + 11410^2 .

It is a cyclic number.

It is not a de Polignac number, because 804161621 - 2¹⁰ = 804160597 is a prime.

Together with 804161623, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_41349035 and since 804161621 and 41349035 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (804161623) 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 as a sum of consecutive naturals, namely, 402080810 + 402080811.

It is an arithmetic number, because the mean of its divisors is an integer number (402080811).

Almost surely, 2^804161621 is an apocalyptic number.

It is an amenable number.

804161621 is a deficient number, since it is larger than the sum of its proper divisors (1).

804161621 is an equidigital number, since it uses as much as digits as its factorization.

804161621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 804161621 is about 28357.7435808987. The cubic root of 804161621 is about 929.9246946385.

The spelling of 804161621 in words is "eight hundred four million, one hundred sixty-one thousand, six hundred twenty-one".