327561781 has 2 divisors, whose sum is σ = 327561782. Its totient is φ = 327561780.

The previous prime is 327561769. The next prime is 327561803. The reversal of 327561781 is 187165723.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 294671556 + 32890225 = 17166^2 + 5735^2 .

It is an emirp because it is prime and its reverse (187165723) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-327561781 is a prime.

It is a super-2 number, since 2×327561781² = 214593440743783922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (327561181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 163780890 + 163780891.

It is an arithmetic number, because the mean of its divisors is an integer number (163780891).

Almost surely, 2^327561781 is an apocalyptic number.

It is an amenable number.

327561781 is a deficient number, since it is larger than the sum of its proper divisors (1).

327561781 is an equidigital number, since it uses as much as digits as its factorization.

327561781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 70560, while the sum is 40.

The square root of 327561781 is about 18098.6679344089. The cubic root of 327561781 is about 689.3361822718.

It can be divided in two parts, 3275 and 61781, that added together give a palindrome (65056).

The spelling of 327561781 in words is "three hundred twenty-seven million, five hundred sixty-one thousand, seven hundred eighty-one".