261320359 has 4 divisors (see below), whose sum is σ = 269750080. Its totient is φ = 252890640.

The previous prime is 261320351. The next prime is 261320393. The reversal of 261320359 is 953023162.

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 261320359 - 2³ = 261320351 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 8429689 = 261320359 / (2 + 6 + 1 + 3 + 2 + 0 + 3 + 5 + 9).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261320359.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261320351) 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, 4214814 + ... + 4214875.

It is an arithmetic number, because the mean of its divisors is an integer number (67437520).

Almost surely, 2^261320359 is an apocalyptic number.

261320359 is a deficient number, since it is larger than the sum of its proper divisors (8429721).

261320359 is an equidigital number, since it uses as much as digits as its factorization.

261320359 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8429720.

The product of its (nonzero) digits is 9720, while the sum is 31.

The square root of 261320359 is about 16165.4062429622. The cubic root of 261320359 is about 639.3290160161.

The spelling of 261320359 in words is "two hundred sixty-one million, three hundred twenty thousand, three hundred fifty-nine".