561488821 has 2 divisors, whose sum is σ = 561488822. Its totient is φ = 561488820.

The previous prime is 561488791. The next prime is 561488831. The reversal of 561488821 is 128884165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 357399025 + 204089796 = 18905^2 + 14286^2 .

It is a cyclic number.

It is not a de Polignac number, because 561488821 - 2¹¹ = 561486773 is a prime.

It is a super-2 number, since 2×561488821² = 630539392215940082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561488831) 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, 280744410 + 280744411.

It is an arithmetic number, because the mean of its divisors is an integer number (280744411).

Almost surely, 2^561488821 is an apocalyptic number.

It is an amenable number.

561488821 is a deficient number, since it is larger than the sum of its proper divisors (1).

561488821 is an equidigital number, since it uses as much as digits as its factorization.

561488821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 122880, while the sum is 43.

The square root of 561488821 is about 23695.7553371907. The cubic root of 561488821 is about 824.9868726408.

The spelling of 561488821 in words is "five hundred sixty-one million, four hundred eighty-eight thousand, eight hundred twenty-one".