394980581 has 2 divisors, whose sum is σ = 394980582. Its totient is φ = 394980580.

The previous prime is 394980577. The next prime is 394980659. The reversal of 394980581 is 185089493.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 274200481 + 120780100 = 16559^2 + 10990^2 .

It is an emirp because it is prime and its reverse (185089493) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 394980581 - 2² = 394980577 is a prime.

It is a super-2 number, since 2×394980581² = 312019318734195122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (394985581) 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, 197490290 + 197490291.

It is an arithmetic number, because the mean of its divisors is an integer number (197490291).

Almost surely, 2^394980581 is an apocalyptic number.

It is an amenable number.

394980581 is a deficient number, since it is larger than the sum of its proper divisors (1).

394980581 is an equidigital number, since it uses as much as digits as its factorization.

394980581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 311040, while the sum is 47.

The square root of 394980581 is about 19874.1183703831. The cubic root of 394980581 is about 733.7113681512.

The spelling of 394980581 in words is "three hundred ninety-four million, nine hundred eighty thousand, five hundred eighty-one".