521090221 has 2 divisors, whose sum is σ = 521090222. Its totient is φ = 521090220.

The previous prime is 521090201. The next prime is 521090237. The reversal of 521090221 is 122090125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 475676100 + 45414121 = 21810^2 + 6739^2 .

It is a cyclic number.

It is not a de Polignac number, because 521090221 - 2⁵ = 521090189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 521090192 and 521090201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521090201) 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, 260545110 + 260545111.

It is an arithmetic number, because the mean of its divisors is an integer number (260545111).

Almost surely, 2^521090221 is an apocalyptic number.

It is an amenable number.

521090221 is a deficient number, since it is larger than the sum of its proper divisors (1).

521090221 is an equidigital number, since it uses as much as digits as its factorization.

521090221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 521090221 is about 22827.4006623619. The cubic root of 521090221 is about 804.7067439978.

The spelling of 521090221 in words is "five hundred twenty-one million, ninety thousand, two hundred twenty-one".