513621 has 20 divisors (see below), whose sum is σ = 814572. Its totient is φ = 321408.

The previous prime is 513593. The next prime is 513631. The reversal of 513621 is 126315.

It can be written as a sum of positive squares in 2 ways, for example, as 342225 + 171396 = 585^2 + 414^2 .

It is not a de Polignac number, because 513621 - 2⁹ = 513109 is a prime.

513621 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 513594 and 513603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (513631) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1191 + ... + 1563.

2⁵¹³⁶²¹ is an apocalyptic number.

513621 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

513621 is a deficient number, since it is larger than the sum of its proper divisors (300951).

513621 is a wasteful number, since it uses less digits than its factorization.

513621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402 (or 393 counting only the distinct ones).

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

The square root of 513621 is about 716.6735658583. The cubic root of 513621 is about 80.0843381406.

Adding to 513621 its reverse (126315), we get a palindrome (639936).

The spelling of 513621 in words is "five hundred thirteen thousand, six hundred twenty-one".