398705679 has 8 divisors (see below), whose sum is σ = 590675120. Its totient is φ = 265803768.

The previous prime is 398705669. The next prime is 398705701. The reversal of 398705679 is 976507893.

398705679 is a `hidden beast` number, since 3 + 9 + 8 + 70 + 567 + 9 = 666.

It is not a de Polignac number, because 398705679 - 2⁷ = 398705551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398705609) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7383412 + ... + 7383465.

It is an arithmetic number, because the mean of its divisors is an integer number (73834390).

Almost surely, 2^398705679 is an apocalyptic number.

398705679 is a deficient number, since it is larger than the sum of its proper divisors (191969441).

398705679 is a wasteful number, since it uses less digits than its factorization.

398705679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14766886 (or 14766880 counting only the distinct ones).

The product of its (nonzero) digits is 2857680, while the sum is 54.

The square root of 398705679 is about 19967.6157565194. The cubic root of 398705679 is about 736.0107211094.

The spelling of 398705679 in words is "three hundred ninety-eight million, seven hundred five thousand, six hundred seventy-nine".