399055549 has 2 divisors, whose sum is σ = 399055550. Its totient is φ = 399055548.

The previous prime is 399055541. The next prime is 399055577. The reversal of 399055549 is 945550993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 206123449 + 192932100 = 14357^2 + 13890^2 .

It is a cyclic number.

It is not a de Polignac number, because 399055549 - 2³ = 399055541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399055541) 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, 199527774 + 199527775.

It is an arithmetic number, because the mean of its divisors is an integer number (199527775).

Almost surely, 2^399055549 is an apocalyptic number.

It is an amenable number.

399055549 is a deficient number, since it is larger than the sum of its proper divisors (1).

399055549 is an equidigital number, since it uses as much as digits as its factorization.

399055549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1093500, while the sum is 49.

The square root of 399055549 is about 19976.3747712141. The cubic root of 399055549 is about 736.2259448520.

It can be divided in two parts, 39905 and 5549, that added together give a palindrome (45454).

The spelling of 399055549 in words is "three hundred ninety-nine million, fifty-five thousand, five hundred forty-nine".