391628161 has 2 divisors, whose sum is σ = 391628162. Its totient is φ = 391628160.

The previous prime is 391628147. The next prime is 391628197. The reversal of 391628161 is 161826193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 388090000 + 3538161 = 19700^2 + 1881^2 .

It is an emirp because it is prime and its reverse (161826193) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 391628161 - 2⁵ = 391628129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 391628161.

It is not a weakly prime, because it can be changed into another prime (391628101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195814080 + 195814081.

It is an arithmetic number, because the mean of its divisors is an integer number (195814081).

Almost surely, 2^391628161 is an apocalyptic number.

It is an amenable number.

391628161 is a deficient number, since it is larger than the sum of its proper divisors (1).

391628161 is an equidigital number, since it uses as much as digits as its factorization.

391628161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 37.

The square root of 391628161 is about 19789.5972925171. The cubic root of 391628161 is about 731.6296618969.

The spelling of 391628161 in words is "three hundred ninety-one million, six hundred twenty-eight thousand, one hundred sixty-one".