320978729 has 2 divisors, whose sum is σ = 320978730. Its totient is φ = 320978728.

The previous prime is 320978719. The next prime is 320978771. The reversal of 320978729 is 927879023.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 300953104 + 20025625 = 17348^2 + 4475^2 .

It is a cyclic number.

It is not a de Polignac number, because 320978729 - 2⁸ = 320978473 is a prime.

It is not a weakly prime, because it can be changed into another prime (320978719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160489364 + 160489365.

It is an arithmetic number, because the mean of its divisors is an integer number (160489365).

Almost surely, 2^320978729 is an apocalyptic number.

It is an amenable number.

320978729 is a deficient number, since it is larger than the sum of its proper divisors (1).

320978729 is an equidigital number, since it uses as much as digits as its factorization.

320978729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 381024, while the sum is 47.

The square root of 320978729 is about 17915.8792416113. The cubic root of 320978729 is about 684.6870035405.

The spelling of 320978729 in words is "three hundred twenty million, nine hundred seventy-eight thousand, seven hundred twenty-nine".