521261 has 8 divisors (see below), whose sum is σ = 568344. Its totient is φ = 475200.

The previous prime is 521251. The next prime is 521267. The reversal of 521261 is 162125.

It can be written as a sum of positive squares in 4 ways, for example, as 155236 + 366025 = 394^2 + 605^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 521261 - 2¹⁴ = 504877 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521267) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1115 + ... + 1511.

It is an arithmetic number, because the mean of its divisors is an integer number (71043).

2⁵²¹²⁶¹ is an apocalyptic number.

It is an amenable number.

521261 is a deficient number, since it is larger than the sum of its proper divisors (47083).

521261 is a wasteful number, since it uses less digits than its factorization.

521261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511.

The product of its digits is 120, while the sum is 17.

The square root of 521261 is about 721.9840718465. The cubic root of 521261 is about 80.4794644325.

Adding to 521261 its reverse (162125), we get a palindrome (683386).

It can be divided in two parts, 521 and 261, that multiplied together give a triangular number (135981 = T₅₂₁).

The spelling of 521261 in words is "five hundred twenty-one thousand, two hundred sixty-one".