394564099819 has 2 divisors, whose sum is σ = 394564099820. Its totient is φ = 394564099818.

The previous prime is 394564099817. The next prime is 394564099873. The reversal of 394564099819 is 918990465493.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 394564099819 - 2¹ = 394564099817 is a prime.

It is a super-2 number, since 2×394564099819² (a number of 24 digits) contains 22 as substring.

Together with 394564099817, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (394564099817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197282049909 + 197282049910.

It is an arithmetic number, because the mean of its divisors is an integer number (197282049910).

Almost surely, 2^394564099819 is an apocalyptic number.

394564099819 is a deficient number, since it is larger than the sum of its proper divisors (1).

394564099819 is an equidigital number, since it uses as much as digits as its factorization.

394564099819 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 75582720, while the sum is 67.

The spelling of 394564099819 in words is "three hundred ninety-four billion, five hundred sixty-four million, ninety-nine thousand, eight hundred nineteen".