261125611 has 4 divisors (see below), whose sum is σ = 262438000. Its totient is φ = 259813224.

The previous prime is 261125603. The next prime is 261125633. The reversal of 261125611 is 116521162.

It is a happy number.

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 261125611 - 2³ = 261125603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261125311) 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 3 ways as a sum of consecutive naturals, for example, 655896 + ... + 656293.

It is an arithmetic number, because the mean of its divisors is an integer number (65609500).

Almost surely, 2^261125611 is an apocalyptic number.

261125611 is a deficient number, since it is larger than the sum of its proper divisors (1312389).

261125611 is a wasteful number, since it uses less digits than its factorization.

261125611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1312388.

The product of its digits is 720, while the sum is 25.

The square root of 261125611 is about 16159.3815166299. The cubic root of 261125611 is about 639.1701573771.

Adding to 261125611 its reverse (116521162), we get a palindrome (377646773).

The spelling of 261125611 in words is "two hundred sixty-one million, one hundred twenty-five thousand, six hundred eleven".