391019 has 2 divisors, whose sum is σ = 391020. Its totient is φ = 391018.

The previous prime is 391009. The next prime is 391021. The reversal of 391019 is 910193.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 391019 - 2⁸ = 390763 is a prime.

It is a super-2 number, since 2×391019² = 305791716722, which contains 22 as substring.

Together with 391021, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 390985 and 391003.

It is not a weakly prime, because it can be changed into another prime (391009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195509 + 195510.

It is an arithmetic number, because the mean of its divisors is an integer number (195510).

2³⁹¹⁰¹⁹ is an apocalyptic number.

391019 is a deficient number, since it is larger than the sum of its proper divisors (1).

391019 is an equidigital number, since it uses as much as digits as its factorization.

391019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 243, while the sum is 23.

The square root of 391019 is about 625.3151205592. The cubic root of 391019 is about 73.1250125405.

The spelling of 391019 in words is "three hundred ninety-one thousand, nineteen".