261109198 has 16 divisors (see below), whose sum is σ = 448180704. Its totient is φ = 111762720.

The previous prime is 261109193. The next prime is 261109207. The reversal of 261109198 is 891901162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261109193) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136 + ... + 22852.

It is an arithmetic number, because the mean of its divisors is an integer number (28011294).

Almost surely, 2^261109198 is an apocalyptic number.

261109198 is a deficient number, since it is larger than the sum of its proper divisors (187071506).

261109198 is a wasteful number, since it uses less digits than its factorization.

261109198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23547.

The product of its (nonzero) digits is 7776, while the sum is 37.

The square root of 261109198 is about 16158.8736612426. The cubic root of 261109198 is about 639.1567654575.

The spelling of 261109198 in words is "two hundred sixty-one million, one hundred nine thousand, one hundred ninety-eight".