261109199 has 4 divisors (see below), whose sum is σ = 281194536. Its totient is φ = 241023864.

The previous prime is 261109193. The next prime is 261109207. The reversal of 261109199 is 991901162.

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 261109199 - 2⁴ = 261109183 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 10042649 + ... + 10042674.

It is an arithmetic number, because the mean of its divisors is an integer number (70298634).

Almost surely, 2^261109199 is an apocalyptic number.

261109199 is a deficient number, since it is larger than the sum of its proper divisors (20085337).

261109199 is a wasteful number, since it uses less digits than its factorization.

261109199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20085336.

The product of its (nonzero) digits is 8748, while the sum is 38.

The square root of 261109199 is about 16158.8736921854. The cubic root of 261109199 is about 639.1567662734.

The spelling of 261109199 in words is "two hundred sixty-one million, one hundred nine thousand, one hundred ninety-nine".