78643198 has 4 divisors (see below), whose sum is σ = 117964800. Its totient is φ = 39321598.

The previous prime is 78643183. The next prime is 78643199. The reversal of 78643198 is 89134687.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78643199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19660798 + ... + 19660801.

It is an arithmetic number, because the mean of its divisors is an integer number (29491200).

Almost surely, 2^78643198 is an apocalyptic number.

78643198 is a deficient number, since it is larger than the sum of its proper divisors (39321602).

78643198 is a wasteful number, since it uses less digits than its factorization.

78643198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39321601.

The product of its digits is 290304, while the sum is 46.

The square root of 78643198 is about 8868.1000219889. The cubic root of 78643198 is about 428.4370844207.

The spelling of 78643198 in words is "seventy-eight million, six hundred forty-three thousand, one hundred ninety-eight".