391228087 has 2 divisors, whose sum is σ = 391228088. Its totient is φ = 391228086.

The previous prime is 391228081. The next prime is 391228127. The reversal of 391228087 is 780822193.

It is an a-pointer prime, because the next prime (391228127) can be obtained adding 391228087 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 391228087 - 2¹⁹ = 390703799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391228081) 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 as a sum of consecutive naturals, namely, 195614043 + 195614044.

It is an arithmetic number, because the mean of its divisors is an integer number (195614044).

Almost surely, 2^391228087 is an apocalyptic number.

391228087 is a deficient number, since it is larger than the sum of its proper divisors (1).

391228087 is an equidigital number, since it uses as much as digits as its factorization.

391228087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 391228087 is about 19779.4865201299. The cubic root of 391228087 is about 731.3804410254.

The spelling of 391228087 in words is "three hundred ninety-one million, two hundred twenty-eight thousand, eighty-seven".