521045621 has 2 divisors, whose sum is σ = 521045622. Its totient is φ = 521045620.

The previous prime is 521045593. The next prime is 521045627. The reversal of 521045621 is 126540125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 519384100 + 1661521 = 22790^2 + 1289^2 .

It is a cyclic number.

It is not a de Polignac number, because 521045621 - 2¹⁰ = 521044597 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521045627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260522810 + 260522811.

It is an arithmetic number, because the mean of its divisors is an integer number (260522811).

Almost surely, 2^521045621 is an apocalyptic number.

It is an amenable number.

521045621 is a deficient number, since it is larger than the sum of its proper divisors (1).

521045621 is an equidigital number, since it uses as much as digits as its factorization.

521045621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 521045621 is about 22826.4237453001. The cubic root of 521045621 is about 804.6837851170.

Adding to 521045621 its reverse (126540125), we get a palindrome (647585746).

The spelling of 521045621 in words is "five hundred twenty-one million, forty-five thousand, six hundred twenty-one".