198640331 has 4 divisors (see below), whose sum is σ = 201033672. Its totient is φ = 196246992.

The previous prime is 198640303. The next prime is 198640357. The reversal of 198640331 is 133046891.

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

It is a cyclic number.

It is not a de Polignac number, because 198640331 - 2¹⁰ = 198639307 is a prime.

It is a super-2 number, since 2×198640331² = 78915962199579122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 198640291 and 198640300.

It is not an unprimeable number, because it can be changed into a prime (198640381) 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, 1196546 + ... + 1196711.

It is an arithmetic number, because the mean of its divisors is an integer number (50258418).

Almost surely, 2^198640331 is an apocalyptic number.

198640331 is a deficient number, since it is larger than the sum of its proper divisors (2393341).

198640331 is an equidigital number, since it uses as much as digits as its factorization.

198640331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2393340.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 198640331 is about 14093.9820845636. The cubic root of 198640331 is about 583.4753010288.

The spelling of 198640331 in words is "one hundred ninety-eight million, six hundred forty thousand, three hundred thirty-one".