521221323 has 16 divisors (see below), whose sum is σ = 801532160. Its totient is φ = 295106976.

The previous prime is 521221231. The next prime is 521221333. The reversal of 521221323 is 323122125.

It is not a de Polignac number, because 521221323 - 2⁸ = 521221067 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 521221323.

It is not an unprimeable number, because it can be changed into a prime (521221333) 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, 111565 + ... + 116142.

It is an arithmetic number, because the mean of its divisors is an integer number (50095760).

Almost surely, 2^521221323 is an apocalyptic number.

521221323 is a deficient number, since it is larger than the sum of its proper divisors (280310837).

521221323 is a wasteful number, since it uses less digits than its factorization.

521221323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227826.

The product of its digits is 720, while the sum is 21.

The square root of 521221323 is about 22830.2720745943. The cubic root of 521221323 is about 804.7742241979.

Adding to 521221323 its reverse (323122125), we get a palindrome (844343448).

The spelling of 521221323 in words is "five hundred twenty-one million, two hundred twenty-one thousand, three hundred twenty-three".