391388377 has 2 divisors, whose sum is σ = 391388378. Its totient is φ = 391388376.

The previous prime is 391388351. The next prime is 391388407. The reversal of 391388377 is 773883193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 349540416 + 41847961 = 18696^2 + 6469^2 .

It is a cyclic number.

It is not a de Polignac number, because 391388377 - 2²⁷ = 257170649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 391388377.

It is not a weakly prime, because it can be changed into another prime (391388177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195694188 + 195694189.

It is an arithmetic number, because the mean of its divisors is an integer number (195694189).

Almost surely, 2^391388377 is an apocalyptic number.

It is an amenable number.

391388377 is a deficient number, since it is larger than the sum of its proper divisors (1).

391388377 is an equidigital number, since it uses as much as digits as its factorization.

391388377 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 49.

The square root of 391388377 is about 19783.5380303928. The cubic root of 391388377 is about 731.4803119770.

The spelling of 391388377 in words is "three hundred ninety-one million, three hundred eighty-eight thousand, three hundred seventy-seven".