399684487 has 2 divisors, whose sum is σ = 399684488. Its totient is φ = 399684486.

The previous prime is 399684479. The next prime is 399684491. The reversal of 399684487 is 784486993.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 399684487 - 2³ = 399684479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399684407) 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, 199842243 + 199842244.

It is an arithmetic number, because the mean of its divisors is an integer number (199842244).

Almost surely, 2^399684487 is an apocalyptic number.

399684487 is a deficient number, since it is larger than the sum of its proper divisors (1).

399684487 is an equidigital number, since it uses as much as digits as its factorization.

399684487 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10450944, while the sum is 58.

The square root of 399684487 is about 19992.1106189417. The cubic root of 399684487 is about 736.6125221313.

The spelling of 399684487 in words is "three hundred ninety-nine million, six hundred eighty-four thousand, four hundred eighty-seven".