328951781 has 2 divisors, whose sum is σ = 328951782. Its totient is φ = 328951780.

The previous prime is 328951771. The next prime is 328951783. The reversal of 328951781 is 187159823.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 327429025 + 1522756 = 18095^2 + 1234^2 .

It is a cyclic number.

It is not a de Polignac number, because 328951781 - 2¹⁸ = 328689637 is a prime.

It is a super-2 number, since 2×328951781² = 216418548446143922, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 328951783, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (328951783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 164475890 + 164475891.

It is an arithmetic number, because the mean of its divisors is an integer number (164475891).

Almost surely, 2^328951781 is an apocalyptic number.

It is an amenable number.

328951781 is a deficient number, since it is larger than the sum of its proper divisors (1).

328951781 is an equidigital number, since it uses as much as digits as its factorization.

328951781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 44.

The square root of 328951781 is about 18137.0278987490. The cubic root of 328951781 is about 690.3098664249.

The spelling of 328951781 in words is "three hundred twenty-eight million, nine hundred fifty-one thousand, seven hundred eighty-one".