328071781 has 4 divisors (see below), whose sum is σ = 328111200. Its totient is φ = 328032364.

The previous prime is 328071773. The next prime is 328071817. The reversal of 328071781 is 187170823.

It is the 7395-th star number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 328071781 - 2³ = 328071773 is a prime.

It is a super-2 number, since 2×328071781² = 215262186977023922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 328071781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (328071721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1801 + ... + 25678.

It is an arithmetic number, because the mean of its divisors is an integer number (82027800).

Almost surely, 2^328071781 is an apocalyptic number.

It is an amenable number.

328071781 is a deficient number, since it is larger than the sum of its proper divisors (39419).

328071781 is a wasteful number, since it uses less digits than its factorization.

328071781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39418.

The product of its (nonzero) digits is 18816, while the sum is 37.

The square root of 328071781 is about 18112.7518892078. The cubic root of 328071781 is about 689.6937526351.

The spelling of 328071781 in words is "three hundred twenty-eight million, seventy-one thousand, seven hundred eighty-one".