545621 has 2 divisors, whose sum is σ = 545622. Its totient is φ = 545620.

The previous prime is 545617. The next prime is 545641. The reversal of 545621 is 126545.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 448900 + 96721 = 670^2 + 311^2 .

It is a cyclic number.

It is not a de Polignac number, because 545621 - 2² = 545617 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (545641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 272810 + 272811.

It is an arithmetic number, because the mean of its divisors is an integer number (272811).

2⁵⁴⁵⁶²¹ is an apocalyptic number.

It is an amenable number.

545621 is a deficient number, since it is larger than the sum of its proper divisors (1).

545621 is an equidigital number, since it uses as much as digits as its factorization.

545621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1200, while the sum is 23.

The square root of 545621 is about 738.6616275400. The cubic root of 545621 is about 81.7141045140.

The spelling of 545621 in words is "five hundred forty-five thousand, six hundred twenty-one".