391238963 has 2 divisors, whose sum is σ = 391238964. Its totient is φ = 391238962.

The previous prime is 391238917. The next prime is 391238987. The reversal of 391238963 is 369832193.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 391238963 - 2¹⁰ = 391237939 is a prime.

It is not a weakly prime, because it can be changed into another prime (391238863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195619481 + 195619482.

It is an arithmetic number, because the mean of its divisors is an integer number (195619482).

Almost surely, 2^391238963 is an apocalyptic number.

391238963 is a deficient number, since it is larger than the sum of its proper divisors (1).

391238963 is an equidigital number, since it uses as much as digits as its factorization.

391238963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 209952, while the sum is 44.

The square root of 391238963 is about 19779.7614495221. The cubic root of 391238963 is about 731.3872183336.

It can be divided in two parts, 3912 and 38963, that added together give a cube (42875 = 35³).

The spelling of 391238963 in words is "three hundred ninety-one million, two hundred thirty-eight thousand, nine hundred sixty-three".