394142779 has 2 divisors, whose sum is σ = 394142780. Its totient is φ = 394142778.

The previous prime is 394142753. The next prime is 394142803. The reversal of 394142779 is 977241493.

It is a strong prime.

It is an emirp because it is prime and its reverse (977241493) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 394142779 - 2¹⁵ = 394110011 is a prime.

It is not a weakly prime, because it can be changed into another prime (394142179) 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, 197071389 + 197071390.

It is an arithmetic number, because the mean of its divisors is an integer number (197071390).

Almost surely, 2^394142779 is an apocalyptic number.

394142779 is a deficient number, since it is larger than the sum of its proper divisors (1).

394142779 is an equidigital number, since it uses as much as digits as its factorization.

394142779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 381024, while the sum is 46.

The square root of 394142779 is about 19853.0294665575. The cubic root of 394142779 is about 733.1922371564.

The spelling of 394142779 in words is "three hundred ninety-four million, one hundred forty-two thousand, seven hundred seventy-nine".