545511821 has 2 divisors, whose sum is σ = 545511822. Its totient is φ = 545511820.

The previous prime is 545511809. The next prime is 545511823. The reversal of 545511821 is 128115545.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 310993225 + 234518596 = 17635^2 + 15314^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-545511821 is a prime.

Together with 545511823, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (545511823) 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 as a sum of consecutive naturals, namely, 272755910 + 272755911.

It is an arithmetic number, because the mean of its divisors is an integer number (272755911).

Almost surely, 2^545511821 is an apocalyptic number.

It is an amenable number.

545511821 is a deficient number, since it is larger than the sum of its proper divisors (1).

545511821 is an equidigital number, since it uses as much as digits as its factorization.

545511821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8000, while the sum is 32.

The square root of 545511821 is about 23356.1944888289. The cubic root of 545511821 is about 817.0865380774.

The spelling of 545511821 in words is "five hundred forty-five million, five hundred eleven thousand, eight hundred twenty-one".