261834569 has 4 divisors (see below), whose sum is σ = 268220820. Its totient is φ = 255448320.

The previous prime is 261834563. The next prime is 261834613. The reversal of 261834569 is 965438162.

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

It can be written as a sum of positive squares in 2 ways, for example, as 53465344 + 208369225 = 7312^2 + 14435^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261834569 is a prime.

It is a super-2 number, since 2×261834569² = 137114683046831522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261834563) 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, 3193064 + ... + 3193145.

It is an arithmetic number, because the mean of its divisors is an integer number (67055205).

Almost surely, 2^261834569 is an apocalyptic number.

It is an amenable number.

261834569 is a deficient number, since it is larger than the sum of its proper divisors (6386251).

261834569 is an equidigital number, since it uses as much as digits as its factorization.

261834569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6386250.

The product of its digits is 311040, while the sum is 44.

The square root of 261834569 is about 16181.3030686654. The cubic root of 261834569 is about 639.7480852627.

The spelling of 261834569 in words is "two hundred sixty-one million, eight hundred thirty-four thousand, five hundred sixty-nine".