320720751 has 24 divisors (see below), whose sum is σ = 500580080. Its totient is φ = 196701696.

The previous prime is 320720749. The next prime is 320720783. The reversal of 320720751 is 157027023.

It is not a de Polignac number, because 320720751 - 2¹ = 320720749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320720731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31455 + ... + 40383.

Almost surely, 2^320720751 is an apocalyptic number.

320720751 is a deficient number, since it is larger than the sum of its proper divisors (179859329).

320720751 is a wasteful number, since it uses less digits than its factorization.

320720751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9255 (or 9252 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 320720751 is about 17908.6780919196. The cubic root of 320720751 is about 684.5035214687.

Adding to 320720751 its reverse (157027023), we get a palindrome (477747774).

The spelling of 320720751 in words is "three hundred twenty million, seven hundred twenty thousand, seven hundred fifty-one".