261641199 has 4 divisors (see below), whose sum is σ = 348854936. Its totient is φ = 174427464.

The previous prime is 261641179. The next prime is 261641249. The reversal of 261641199 is 991146162.

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

It is not a de Polignac number, because 261641199 - 2⁵ = 261641167 is a prime.

It is a super-2 number, since 2×261641199² = 136912234028315202, 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 (261641179) 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, 43606864 + ... + 43606869.

It is an arithmetic number, because the mean of its divisors is an integer number (87213734).

Almost surely, 2^261641199 is an apocalyptic number.

261641199 is a deficient number, since it is larger than the sum of its proper divisors (87213737).

261641199 is an equidigital number, since it uses as much as digits as its factorization.

261641199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87213736.

The product of its digits is 23328, while the sum is 39.

The square root of 261641199 is about 16175.3268591395. The cubic root of 261641199 is about 639.5905576123.

The spelling of 261641199 in words is "two hundred sixty-one million, six hundred forty-one thousand, one hundred ninety-nine".