261231143 has 2 divisors, whose sum is σ = 261231144. Its totient is φ = 261231142.

The previous prime is 261231127. The next prime is 261231151. The reversal of 261231143 is 341132162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261231143 - 2⁴ = 261231127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261231193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130615571 + 130615572.

It is an arithmetic number, because the mean of its divisors is an integer number (130615572).

Almost surely, 2^261231143 is an apocalyptic number.

261231143 is a deficient number, since it is larger than the sum of its proper divisors (1).

261231143 is an equidigital number, since it uses as much as digits as its factorization.

261231143 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 261231143 is about 16162.6465345252. The cubic root of 261231143 is about 639.2562510901.

The spelling of 261231143 in words is "two hundred sixty-one million, two hundred thirty-one thousand, one hundred forty-three".