261580551 has 16 divisors (see below), whose sum is σ = 364316160. Its totient is φ = 166733280.

The previous prime is 261580537. The next prime is 261580577. The reversal of 261580551 is 155085162.

It is not a de Polignac number, because 261580551 - 2⁵ = 261580519 is a prime.

It is a super-2 number, since 2×261580551² = 136848769322927202, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261580531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5635 + ... + 23556.

It is an arithmetic number, because the mean of its divisors is an integer number (22769760).

Almost surely, 2^261580551 is an apocalyptic number.

261580551 is a deficient number, since it is larger than the sum of its proper divisors (102735609).

261580551 is a wasteful number, since it uses less digits than its factorization.

261580551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29326.

The product of its (nonzero) digits is 12000, while the sum is 33.

The square root of 261580551 is about 16173.4520433951. The cubic root of 261580551 is about 639.5411351133.

The spelling of 261580551 in words is "two hundred sixty-one million, five hundred eighty thousand, five hundred fifty-one".