613521 has 16 divisors (see below), whose sum is σ = 939520. Its totient is φ = 395280.

The previous prime is 613507. The next prime is 613523. The reversal of 613521 is 125316.

613521 is a `hidden beast` number, since 613 + 52 + 1 = 666.

It is not a de Polignac number, because 613521 - 2⁹ = 613009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 613494 and 613503.

It is not an unprimeable number, because it can be changed into a prime (613523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 471 + ... + 1203.

It is an arithmetic number, because the mean of its divisors is an integer number (58720).

2⁶¹³⁵²¹ is an apocalyptic number.

It is an amenable number.

613521 is a deficient number, since it is larger than the sum of its proper divisors (325999).

613521 is a wasteful number, since it uses less digits than its factorization.

613521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773 (or 767 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 613521 is about 783.2758134910. The cubic root of 613521 is about 84.9721246541.

Adding to 613521 its reverse (125316), we get a palindrome (738837).

The spelling of 613521 in words is "six hundred thirteen thousand, five hundred twenty-one".