521749 has 2 divisors, whose sum is σ = 521750. Its totient is φ = 521748.

The previous prime is 521743. The next prime is 521753. The reversal of 521749 is 947125.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 442225 + 79524 = 665^2 + 282^2 .

It is a cyclic number.

It is not a de Polignac number, because 521749 - 2¹⁵ = 488981 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 (521743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260874 + 260875.

It is an arithmetic number, because the mean of its divisors is an integer number (260875).

2⁵²¹⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

521749 is a deficient number, since it is larger than the sum of its proper divisors (1).

521749 is an equidigital number, since it uses as much as digits as its factorization.

521749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2520, while the sum is 28.

The square root of 521749 is about 722.3219503795. The cubic root of 521749 is about 80.5045713233.

The spelling of 521749 in words is "five hundred twenty-one thousand, seven hundred forty-nine".