545408221 has 4 divisors (see below), whose sum is σ = 545556700. Its totient is φ = 545259744.

The previous prime is 545408209. The next prime is 545408267. The reversal of 545408221 is 122804545.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122804545 = 5 ⋅24560909.

It can be written as a sum of positive squares in 2 ways, for example, as 230736100 + 314672121 = 15190^2 + 17739^2 .

It is a cyclic number.

It is not a de Polignac number, because 545408221 - 2²⁵ = 511853789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (545408321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68586 + ... + 76123.

It is an arithmetic number, because the mean of its divisors is an integer number (136389175).

Almost surely, 2^545408221 is an apocalyptic number.

It is an amenable number.

545408221 is a deficient number, since it is larger than the sum of its proper divisors (148479).

545408221 is a wasteful number, since it uses less digits than its factorization.

545408221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148478.

The product of its (nonzero) digits is 12800, while the sum is 31.

The square root of 545408221 is about 23353.9765564668. The cubic root of 545408221 is about 817.0348095774.

The spelling of 545408221 in words is "five hundred forty-five million, four hundred eight thousand, two hundred twenty-one".