320488991 has 2 divisors, whose sum is σ = 320488992. Its totient is φ = 320488990.

The previous prime is 320488963. The next prime is 320488997. The reversal of 320488991 is 199884023.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (199884023) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 320488991 - 2¹⁰ = 320487967 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (320488997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160244495 + 160244496.

It is an arithmetic number, because the mean of its divisors is an integer number (160244496).

Almost surely, 2^320488991 is an apocalyptic number.

320488991 is a deficient number, since it is larger than the sum of its proper divisors (1).

320488991 is an equidigital number, since it uses as much as digits as its factorization.

320488991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 320488991 is about 17902.2063165410. The cubic root of 320488991 is about 684.3386025443.

The spelling of 320488991 in words is "three hundred twenty million, four hundred eighty-eight thousand, nine hundred ninety-one".