521551 has 2 divisors, whose sum is σ = 521552. Its totient is φ = 521550.

The previous prime is 521539. The next prime is 521557. The reversal of 521551 is 155125.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 521551 - 2⁵ = 521519 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 (521557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260775 + 260776.

It is an arithmetic number, because the mean of its divisors is an integer number (260776).

2⁵²¹⁵⁵¹ is an apocalyptic number.

521551 is a deficient number, since it is larger than the sum of its proper divisors (1).

521551 is an equidigital number, since it uses as much as digits as its factorization.

521551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 250, while the sum is 19.

The square root of 521551 is about 722.1848793765. The cubic root of 521551 is about 80.4943863992.

Adding to 521551 its reverse (155125), we get a palindrome (676676).

The spelling of 521551 in words is "five hundred twenty-one thousand, five hundred fifty-one".