545551021 has 2 divisors, whose sum is σ = 545551022. Its totient is φ = 545551020.

The previous prime is 545551003. The next prime is 545551033. The reversal of 545551021 is 120155545.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 528494121 + 17056900 = 22989^2 + 4130^2 .

It is a cyclic number.

It is not a de Polignac number, because 545551021 - 2¹¹ = 545548973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (545551081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 272775510 + 272775511.

It is an arithmetic number, because the mean of its divisors is an integer number (272775511).

Almost surely, 2^545551021 is an apocalyptic number.

It is an amenable number.

545551021 is a deficient number, since it is larger than the sum of its proper divisors (1).

545551021 is an equidigital number, since it uses as much as digits as its factorization.

545551021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5000, while the sum is 28.

The square root of 545551021 is about 23357.0336515577. The cubic root of 545551021 is about 817.1061093154.

The spelling of 545551021 in words is "five hundred forty-five million, five hundred fifty-one thousand, twenty-one".