398899639 has 2 divisors, whose sum is σ = 398899640. Its totient is φ = 398899638.

The previous prime is 398899621. The next prime is 398899643. The reversal of 398899639 is 936998893.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 398899639 - 2¹³ = 398891447 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398899139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199449819 + 199449820.

It is an arithmetic number, because the mean of its divisors is an integer number (199449820).

Almost surely, 2^398899639 is an apocalyptic number.

398899639 is a deficient number, since it is larger than the sum of its proper divisors (1).

398899639 is an equidigital number, since it uses as much as digits as its factorization.

398899639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22674816, while the sum is 64.

The square root of 398899639 is about 19972.4720302721. The cubic root of 398899639 is about 736.1300518205.

The spelling of 398899639 in words is "three hundred ninety-eight million, eight hundred ninety-nine thousand, six hundred thirty-nine".