521993 has 2 divisors, whose sum is σ = 521994. Its totient is φ = 521992.

The previous prime is 521981. The next prime is 521999. The reversal of 521993 is 399125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 299209 + 222784 = 547^2 + 472^2 .

It is a cyclic number.

It is not a de Polignac number, because 521993 - 2⁶ = 521929 is a prime.

It is a Chen prime.

It is a nialpdrome in base 14.

It is not a weakly prime, because it can be changed into another prime (521999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260996 + 260997.

It is an arithmetic number, because the mean of its divisors is an integer number (260997).

2⁵²¹⁹⁹³ is an apocalyptic number.

It is an amenable number.

521993 is a deficient number, since it is larger than the sum of its proper divisors (1).

521993 is an equidigital number, since it uses as much as digits as its factorization.

521993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2430, while the sum is 29.

The square root of 521993 is about 722.4908303916. The cubic root of 521993 is about 80.5171188983.

The spelling of 521993 in words is "five hundred twenty-one thousand, nine hundred ninety-three".