320636891 has 2 divisors, whose sum is σ = 320636892. Its totient is φ = 320636890.

The previous prime is 320636863. The next prime is 320636917. The reversal of 320636891 is 198636023.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-320636891 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (320636821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160318445 + 160318446.

It is an arithmetic number, because the mean of its divisors is an integer number (160318446).

Almost surely, 2^320636891 is an apocalyptic number.

320636891 is a deficient number, since it is larger than the sum of its proper divisors (1).

320636891 is an equidigital number, since it uses as much as digits as its factorization.

320636891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 38.

The square root of 320636891 is about 17906.3366158464. The cubic root of 320636891 is about 684.4438564082.

The spelling of 320636891 in words is "three hundred twenty million, six hundred thirty-six thousand, eight hundred ninety-one".