391191628469 has 2 divisors, whose sum is σ = 391191628470. Its totient is φ = 391191628468.

The previous prime is 391191628453. The next prime is 391191628511. The reversal of 391191628469 is 964826191193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 378578092369 + 12613536100 = 615287^2 + 112310^2 .

It is a cyclic number.

It is not a de Polignac number, because 391191628469 - 2⁴ = 391191628453 is a prime.

It is a super-2 number, since 2×391191628469² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391191628409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195595814234 + 195595814235.

It is an arithmetic number, because the mean of its divisors is an integer number (195595814235).

Almost surely, 2^391191628469 is an apocalyptic number.

It is an amenable number.

391191628469 is a deficient number, since it is larger than the sum of its proper divisors (1).

391191628469 is an equidigital number, since it uses as much as digits as its factorization.

391191628469 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5038848, while the sum is 59.

The spelling of 391191628469 in words is "three hundred ninety-one billion, one hundred ninety-one million, six hundred twenty-eight thousand, four hundred sixty-nine".