261130905 has 64 divisors (see below), whose sum is σ = 534689280. Its totient is φ = 118444032.

The previous prime is 261130901. The next prime is 261130907. The reversal of 261130905 is 509031162.

It is not a de Polignac number, because 261130905 - 2² = 261130901 is a prime.

It is a super-2 number, since 2×261130905² = 136378699092238050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (261130901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 128457 + ... + 130473.

It is an arithmetic number, because the mean of its divisors is an integer number (8354520).

Almost surely, 2^261130905 is an apocalyptic number.

It is an amenable number.

261130905 is an abundant number, since it is smaller than the sum of its proper divisors (273558375).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261130905 is a wasteful number, since it uses less digits than its factorization.

261130905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2175 (or 2169 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 261130905 is about 16159.5453215739. The cubic root of 261130905 is about 639.1744768104.

The spelling of 261130905 in words is "two hundred sixty-one million, one hundred thirty thousand, nine hundred five".