394777861 has 2 divisors, whose sum is σ = 394777862. Its totient is φ = 394777860.

The previous prime is 394777853. The next prime is 394777871. The reversal of 394777861 is 168777493.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 368409636 + 26368225 = 19194^2 + 5135^2 .

It is a cyclic number.

It is not a de Polignac number, because 394777861 - 2³ = 394777853 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 394777799 and 394777808.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (394777871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197388930 + 197388931.

It is an arithmetic number, because the mean of its divisors is an integer number (197388931).

Almost surely, 2^394777861 is an apocalyptic number.

It is an amenable number.

394777861 is a deficient number, since it is larger than the sum of its proper divisors (1).

394777861 is an equidigital number, since it uses as much as digits as its factorization.

394777861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1778112, while the sum is 52.

The square root of 394777861 is about 19869.0176153729. The cubic root of 394777861 is about 733.5858232265.

The spelling of 394777861 in words is "three hundred ninety-four million, seven hundred seventy-seven thousand, eight hundred sixty-one".