261130661569 has 4 divisors (see below), whose sum is σ = 267203467696. Its totient is φ = 255057855444.

The previous prime is 261130661509. The next prime is 261130661609. The reversal of 261130661569 is 965166031162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261130661569 - 2¹¹ = 261130659521 is a prime.

It is a super-2 number, since 2×261130661569² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261130661509) 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, 3036402999 + ... + 3036403084.

It is an arithmetic number, because the mean of its divisors is an integer number (66800866924).

Almost surely, 2^261130661569 is an apocalyptic number.

It is an amenable number.

261130661569 is a deficient number, since it is larger than the sum of its proper divisors (6072806127).

261130661569 is an equidigital number, since it uses as much as digits as its factorization.

261130661569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6072806126.

The product of its (nonzero) digits is 349920, while the sum is 46.

The spelling of 261130661569 in words is "two hundred sixty-one billion, one hundred thirty million, six hundred sixty-one thousand, five hundred sixty-nine".