394086661 has 2 divisors, whose sum is σ = 394086662. Its totient is φ = 394086660.

The previous prime is 394086659. The next prime is 394086677. The reversal of 394086661 is 166680493.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 392277636 + 1809025 = 19806^2 + 1345^2 .

It is a cyclic number.

It is not a de Polignac number, because 394086661 - 2¹ = 394086659 is a prime.

Together with 394086659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (394086611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197043330 + 197043331.

It is an arithmetic number, because the mean of its divisors is an integer number (197043331).

Almost surely, 2^394086661 is an apocalyptic number.

It is an amenable number.

394086661 is a deficient number, since it is larger than the sum of its proper divisors (1).

394086661 is an equidigital number, since it uses as much as digits as its factorization.

394086661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 43.

The square root of 394086661 is about 19851.6160803094. The cubic root of 394086661 is about 733.1574382315.

It can be divided in two parts, 3940 and 86661, that added together give a square (90601 = 301²).

The spelling of 394086661 in words is "three hundred ninety-four million, eighty-six thousand, six hundred sixty-one".