197639427018 has 128 divisors (see below), whose sum is σ = 453466128384. Its totient is φ = 56842315200.

The previous prime is 197639427017. The next prime is 197639427103. The reversal of 197639427018 is 810724936791.

It is a happy number.

It is a super-2 number, since 2×197639427018² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (197639427017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 175991805 + ... + 175992927.

It is an arithmetic number, because the mean of its divisors is an integer number (3542704128).

Almost surely, 2^197639427018 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 197639427018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (226733064192).

197639427018 is an abundant number, since it is smaller than the sum of its proper divisors (255826701366).

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

197639427018 is a wasteful number, since it uses less digits than its factorization.

197639427018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1960.

The product of its (nonzero) digits is 4572288, while the sum is 57.

The spelling of 197639427018 in words is "one hundred ninety-seven billion, six hundred thirty-nine million, four hundred twenty-seven thousand, eighteen".