198278778 has 16 divisors (see below), whose sum is σ = 396829440. Its totient is φ = 66047616.

The previous prime is 198278753. The next prime is 198278797. The reversal of 198278778 is 877872891.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1143 + ... + 19946.

It is an arithmetic number, because the mean of its divisors is an integer number (24801840).

Almost surely, 2^198278778 is an apocalyptic number.

198278778 is an abundant number, since it is smaller than the sum of its proper divisors (198550662).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

198278778 is a wasteful number, since it uses less digits than its factorization.

198278778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22661.

The product of its digits is 3161088, while the sum is 57.

The square root of 198278778 is about 14081.1497399893. The cubic root of 198278778 is about 583.1210839966.

The spelling of 198278778 in words is "one hundred ninety-eight million, two hundred seventy-eight thousand, seven hundred seventy-eight".