261143321 has 2 divisors, whose sum is σ = 261143322. Its totient is φ = 261143320.

The previous prime is 261143291. The next prime is 261143329. The reversal of 261143321 is 123341162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 249987721 + 11155600 = 15811^2 + 3340^2 .

It is a cyclic number.

It is not a de Polignac number, because 261143321 - 2²⁶ = 194034457 is a prime.

It is not a weakly prime, because it can be changed into another prime (261143329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130571660 + 130571661.

It is an arithmetic number, because the mean of its divisors is an integer number (130571661).

Almost surely, 2^261143321 is an apocalyptic number.

It is an amenable number.

261143321 is a deficient number, since it is larger than the sum of its proper divisors (1).

261143321 is an equidigital number, since it uses as much as digits as its factorization.

261143321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 23.

The square root of 261143321 is about 16159.9294862323. The cubic root of 261143321 is about 639.1846069333.

Adding to 261143321 its reverse (123341162), we get a palindrome (384484483).

The spelling of 261143321 in words is "two hundred sixty-one million, one hundred forty-three thousand, three hundred twenty-one".