197798778 has 48 divisors (see below), whose sum is σ = 456892800. Its totient is φ = 61663680.

The previous prime is 197798773. The next prime is 197798779. The reversal of 197798778 is 877897791.

It is a happy number.

197798778 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (197798771) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23358 + ... + 30678.

It is an arithmetic number, because the mean of its divisors is an integer number (9518600).

Almost surely, 2^197798778 is an apocalyptic number.

197798778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 197798778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (228446400).

197798778 is an abundant number, since it is smaller than the sum of its proper divisors (259094022).

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

197798778 is a wasteful number, since it uses less digits than its factorization.

197798778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7427 (or 7424 counting only the distinct ones).

The product of its digits is 12446784, while the sum is 63.

The square root of 197798778 is about 14064.0953495061. The cubic root of 197798778 is about 582.6501573385.

The spelling of 197798778 in words is "one hundred ninety-seven million, seven hundred ninety-eight thousand, seven hundred seventy-eight".