521545 has 4 divisors (see below), whose sum is σ = 625860. Its totient is φ = 417232.

The previous prime is 521539. The next prime is 521551. The reversal of 521545 is 545125.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (521539) and next prime (521551).

It can be written as a sum of positive squares in 2 ways, for example, as 383161 + 138384 = 619^2 + 372^2 .

It is a cyclic number.

It is not a de Polignac number, because 521545 - 2³ = 521537 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52150 + ... + 52159.

It is an arithmetic number, because the mean of its divisors is an integer number (156465).

2⁵²¹⁵⁴⁵ is an apocalyptic number.

It is an amenable number.

521545 is a deficient number, since it is larger than the sum of its proper divisors (104315).

521545 is a wasteful number, since it uses less digits than its factorization.

521545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104314.

The product of its digits is 1000, while the sum is 22.

The square root of 521545 is about 722.1807253036. The cubic root of 521545 is about 80.4940777249.

The spelling of 521545 in words is "five hundred twenty-one thousand, five hundred forty-five".