320522721 has 4 divisors (see below), whose sum is σ = 427363632. Its totient is φ = 213681812.

The previous prime is 320522693. The next prime is 320522737. The reversal of 320522721 is 127225023.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 320522721 - 2¹³ = 320514529 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 320522691 and 320522700.

It is not an unprimeable number, because it can be changed into a prime (320522771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53420451 + ... + 53420456.

It is an arithmetic number, because the mean of its divisors is an integer number (106840908).

Almost surely, 2^320522721 is an apocalyptic number.

It is an amenable number.

320522721 is a deficient number, since it is larger than the sum of its proper divisors (106840911).

320522721 is a wasteful number, since it uses less digits than its factorization.

320522721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106840910.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 320522721 is about 17903.1483544096. The cubic root of 320522721 is about 684.3626095378.

Adding to 320522721 its reverse (127225023), we get a palindrome (447747744).

The spelling of 320522721 in words is "three hundred twenty million, five hundred twenty-two thousand, seven hundred twenty-one".