198551478361 has 4 divisors (see below), whose sum is σ = 198777877732. Its totient is φ = 198325078992.

The previous prime is 198551478347. The next prime is 198551478373. The reversal of 198551478361 is 163874155891.

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

It can be written as a sum of positive squares in 2 ways, for example, as 187540963600 + 11010514761 = 433060^2 + 104931^2 .

It is a cyclic number.

It is not a de Polignac number, because 198551478361 - 2¹⁵ = 198551445593 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 198551478296 and 198551478305.

It is not an unprimeable number, because it can be changed into a prime (198551478311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113198370 + ... + 113200123.

It is an arithmetic number, because the mean of its divisors is an integer number (49694469433).

Almost surely, 2^198551478361 is an apocalyptic number.

It is an amenable number.

198551478361 is a deficient number, since it is larger than the sum of its proper divisors (226399371).

198551478361 is an equidigital number, since it uses as much as digits as its factorization.

198551478361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226399370.

The product of its digits is 7257600, while the sum is 58.

The spelling of 198551478361 in words is "one hundred ninety-eight billion, five hundred fifty-one million, four hundred seventy-eight thousand, three hundred sixty-one".