320120021 has 4 divisors (see below), whose sum is σ = 344744652. Its totient is φ = 295495392.

The previous prime is 320119991. The next prime is 320120023. The reversal of 320120021 is 120021023.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 146143921 + 173976100 = 12089^2 + 13190^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-320120021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 320119984 and 320120011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320120023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12312296 + ... + 12312321.

It is an arithmetic number, because the mean of its divisors is an integer number (86186163).

Almost surely, 2^320120021 is an apocalyptic number.

It is an amenable number.

320120021 is a deficient number, since it is larger than the sum of its proper divisors (24624631).

320120021 is a wasteful number, since it uses less digits than its factorization.

320120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24624630.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 320120021 is about 17891.8981944343. The cubic root of 320120021 is about 684.0758817414.

Adding to 320120021 its reverse (120021023), we get a palindrome (440141044).

The spelling of 320120021 in words is "three hundred twenty million, one hundred twenty thousand, twenty-one".