521897213 has 2 divisors, whose sum is σ = 521897214. Its totient is φ = 521897212.

The previous prime is 521897191. The next prime is 521897219. The reversal of 521897213 is 312798125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 355435609 + 166461604 = 18853^2 + 12902^2 .

It is a cyclic number.

It is not a de Polignac number, because 521897213 - 2¹² = 521893117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (521897219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260948606 + 260948607.

It is an arithmetic number, because the mean of its divisors is an integer number (260948607).

Almost surely, 2^521897213 is an apocalyptic number.

It is an amenable number.

521897213 is a deficient number, since it is larger than the sum of its proper divisors (1).

521897213 is an equidigital number, since it uses as much as digits as its factorization.

521897213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 38.

The square root of 521897213 is about 22845.0697744612. The cubic root of 521897213 is about 805.1219356718.

The spelling of 521897213 in words is "five hundred twenty-one million, eight hundred ninety-seven thousand, two hundred thirteen".