521726417 has 2 divisors, whose sum is σ = 521726418. Its totient is φ = 521726416.

The previous prime is 521726393. The next prime is 521726419. The reversal of 521726417 is 714627125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 272118016 + 249608401 = 16496^2 + 15799^2 .

It is a cyclic number.

It is not a de Polignac number, because 521726417 - 2¹² = 521722321 is a prime.

Together with 521726419, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (521726419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260863208 + 260863209.

It is an arithmetic number, because the mean of its divisors is an integer number (260863209).

Almost surely, 2^521726417 is an apocalyptic number.

It is an amenable number.

521726417 is a deficient number, since it is larger than the sum of its proper divisors (1).

521726417 is an equidigital number, since it uses as much as digits as its factorization.

521726417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23520, while the sum is 35.

The square root of 521726417 is about 22841.3313316015. The cubic root of 521726417 is about 805.0340980631.

The spelling of 521726417 in words is "five hundred twenty-one million, seven hundred twenty-six thousand, four hundred seventeen".