261021113 has 4 divisors (see below), whose sum is σ = 262373748. Its totient is φ = 259668480.

The previous prime is 261021109. The next prime is 261021121. The reversal of 261021113 is 311120162.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51437584 + 209583529 = 7172^2 + 14477^2 .

It is a cyclic number.

It is not a de Polignac number, because 261021113 - 2² = 261021109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261021091 and 261021100.

It is not an unprimeable number, because it can be changed into a prime (261021143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 676028 + ... + 676413.

It is an arithmetic number, because the mean of its divisors is an integer number (65593437).

Almost surely, 2^261021113 is an apocalyptic number.

It is an amenable number.

261021113 is a deficient number, since it is larger than the sum of its proper divisors (1352635).

261021113 is a wasteful number, since it uses less digits than its factorization.

261021113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1352634.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 261021113 is about 16156.1478391354. The cubic root of 261021113 is about 639.0848843489.

Adding to 261021113 its reverse (311120162), we get a palindrome (572141275).

The spelling of 261021113 in words is "two hundred sixty-one million, twenty-one thousand, one hundred thirteen".