261618743 has 2 divisors, whose sum is σ = 261618744. Its totient is φ = 261618742.

The previous prime is 261618727. The next prime is 261618769. The reversal of 261618743 is 347816162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261618743 - 2⁴ = 261618727 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261618697 and 261618706.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261618713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130809371 + 130809372.

It is an arithmetic number, because the mean of its divisors is an integer number (130809372).

Almost surely, 2^261618743 is an apocalyptic number.

261618743 is a deficient number, since it is larger than the sum of its proper divisors (1).

261618743 is an equidigital number, since it uses as much as digits as its factorization.

261618743 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 38.

The square root of 261618743 is about 16174.6327006211. The cubic root of 261618743 is about 639.5722589440.

The spelling of 261618743 in words is "two hundred sixty-one million, six hundred eighteen thousand, seven hundred forty-three".