804127561 has 2 divisors, whose sum is σ = 804127562. Its totient is φ = 804127560.

The previous prime is 804127531. The next prime is 804127567. The reversal of 804127561 is 165721408.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 648975625 + 155151936 = 25475^2 + 12456^2 .

It is a cyclic number.

It is not a de Polignac number, because 804127561 - 2¹¹ = 804125513 is a prime.

It is a super-2 number, since 2×804127561² = 1293242268719617442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (804127567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402063780 + 402063781.

It is an arithmetic number, because the mean of its divisors is an integer number (402063781).

Almost surely, 2^804127561 is an apocalyptic number.

It is an amenable number.

804127561 is a deficient number, since it is larger than the sum of its proper divisors (1).

804127561 is an equidigital number, since it uses as much as digits as its factorization.

804127561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 804127561 is about 28357.1430331054. The cubic root of 804127561 is about 929.9115655687.

Adding to 804127561 its reverse (165721408), we get a palindrome (969848969).

The spelling of 804127561 in words is "eight hundred four million, one hundred twenty-seven thousand, five hundred sixty-one".