261121121 has 8 divisors (see below), whose sum is σ = 263719104. Its totient is φ = 258532560.

The previous prime is 261121103. The next prime is 261121141. The reversal of 261121121 is 121121162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261121121 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 261121121.

It is not an unprimeable number, because it can be changed into a prime (261121141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61751 + ... + 65843.

It is an arithmetic number, because the mean of its divisors is an integer number (32964888).

Almost surely, 2^261121121 is an apocalyptic number.

It is an amenable number.

261121121 is a deficient number, since it is larger than the sum of its proper divisors (2597983).

261121121 is a wasteful number, since it uses less digits than its factorization.

261121121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4711.

The product of its digits is 48, while the sum is 17.

The square root of 261121121 is about 16159.2425874482. The cubic root of 261121121 is about 639.1664938906.

Adding to 261121121 its reverse (121121162), we get a palindrome (382242283).

It can be divided in two parts, 261121 and 121, that multiplied together give a square (31595641 = 5621²).

The spelling of 261121121 in words is "two hundred sixty-one million, one hundred twenty-one thousand, one hundred twenty-one".