3998401639 has 2 divisors, whose sum is σ = 3998401640. Its totient is φ = 3998401638.

The previous prime is 3998401577. The next prime is 3998401643. The reversal of 3998401639 is 9361048993.

It is a strong prime.

It is an emirp because it is prime and its reverse (9361048993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3998401639 - 2²⁹ = 3461530727 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3998401699) 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, 1999200819 + 1999200820.

It is an arithmetic number, because the mean of its divisors is an integer number (1999200820).

Almost surely, 2^3998401639 is an apocalyptic number.

3998401639 is a deficient number, since it is larger than the sum of its proper divisors (1).

3998401639 is an equidigital number, since it uses as much as digits as its factorization.

3998401639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1259712, while the sum is 52.

The square root of 3998401639 is about 63232.9157875865. The cubic root of 3998401639 is about 1587.1895871382.

The spelling of 3998401639 in words is "three billion, nine hundred ninety-eight million, four hundred one thousand, six hundred thirty-nine".