515421 has 6 divisors (see below), whose sum is σ = 744510. Its totient is φ = 343608.

The previous prime is 515401. The next prime is 515429. The reversal of 515421 is 124515.

It can be written as a sum of positive squares in only one way, i.e., 509796 + 5625 = 714^2 + 75^2 .

It is not a de Polignac number, because 515421 - 2⁶ = 515357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 515394 and 515403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (515429) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28626 + ... + 28643.

It is an arithmetic number, because the mean of its divisors is an integer number (124085).

2⁵¹⁵⁴²¹ is an apocalyptic number.

It is an amenable number.

515421 is a deficient number, since it is larger than the sum of its proper divisors (229089).

515421 is a wasteful number, since it uses less digits than its factorization.

515421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57275 (or 57272 counting only the distinct ones).

The product of its digits is 200, while the sum is 18.

The square root of 515421 is about 717.9282693974. The cubic root of 515421 is about 80.1777817115.

Adding to 515421 its reverse (124515), we get a palindrome (639936).

The spelling of 515421 in words is "five hundred fifteen thousand, four hundred twenty-one".