398855878 has 4 divisors (see below), whose sum is σ = 598283820. Its totient is φ = 199427938.

The previous prime is 398855869. The next prime is 398855939. The reversal of 398855878 is 878558893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 878558893 = 1787 ⋅491639.

It is a super-2 number, since 2×398855878² = 318172022830301768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99713968 + ... + 99713971.

It is an arithmetic number, because the mean of its divisors is an integer number (149570955).

Almost surely, 2^398855878 is an apocalyptic number.

398855878 is a deficient number, since it is larger than the sum of its proper divisors (199427942).

398855878 is a wasteful number, since it uses less digits than its factorization.

398855878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199427941.

The product of its digits is 19353600, while the sum is 61.

The square root of 398855878 is about 19971.3764673344. The cubic root of 398855878 is about 736.1031319622.

The spelling of 398855878 in words is "three hundred ninety-eight million, eight hundred fifty-five thousand, eight hundred seventy-eight".