261855089 has 8 divisors (see below), whose sum is σ = 265517280. Its totient is φ = 258212736.

The previous prime is 261855073. The next prime is 261855103. The reversal of 261855089 is 980558162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261855089 - 2⁴ = 261855073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261855019) 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, 22682 + ... + 32220.

It is an arithmetic number, because the mean of its divisors is an integer number (33189660).

Almost surely, 2^261855089 is an apocalyptic number.

It is an amenable number.

261855089 is a deficient number, since it is larger than the sum of its proper divisors (3662191).

261855089 is an equidigital number, since it uses as much as digits as its factorization.

261855089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9919.

The product of its (nonzero) digits is 172800, while the sum is 44.

The square root of 261855089 is about 16181.9371213709. The cubic root of 261855089 is about 639.7647971988.

The spelling of 261855089 in words is "two hundred sixty-one million, eight hundred fifty-five thousand, eighty-nine".