198214781 has 4 divisors (see below), whose sum is σ = 209874492. Its totient is φ = 186555072.

The previous prime is 198214777. The next prime is 198214789. The reversal of 198214781 is 187412891.

198214781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 187412891 = 3299 ⋅56809.

It can be written as a sum of positive squares in 2 ways, for example, as 70728100 + 127486681 = 8410^2 + 11291^2 .

It is a cyclic number.

It is not a de Polignac number, because 198214781 - 2² = 198214777 is a prime.

It is a super-2 number, since 2×198214781² = 78578198813755922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198214789) 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, 5829830 + ... + 5829863.

It is an arithmetic number, because the mean of its divisors is an integer number (52468623).

Almost surely, 2^198214781 is an apocalyptic number.

It is an amenable number.

198214781 is a deficient number, since it is larger than the sum of its proper divisors (11659711).

198214781 is a wasteful number, since it uses less digits than its factorization.

198214781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11659710.

The product of its digits is 32256, while the sum is 41.

The square root of 198214781 is about 14078.8771214185. The cubic root of 198214781 is about 583.0583406611.

The spelling of 198214781 in words is "one hundred ninety-eight million, two hundred fourteen thousand, seven hundred eighty-one".