261006257 has 2 divisors, whose sum is σ = 261006258. Its totient is φ = 261006256.

The previous prime is 261006247. The next prime is 261006269. The reversal of 261006257 is 752600162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 187115041 + 73891216 = 13679^2 + 8596^2 .

It is a cyclic number.

It is not a de Polignac number, because 261006257 - 2¹⁶ = 260940721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (261006217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130503128 + 130503129.

It is an arithmetic number, because the mean of its divisors is an integer number (130503129).

Almost surely, 2^261006257 is an apocalyptic number.

It is an amenable number.

261006257 is a deficient number, since it is larger than the sum of its proper divisors (1).

261006257 is an equidigital number, since it uses as much as digits as its factorization.

261006257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 261006257 is about 16155.6880695314. The cubic root of 261006257 is about 639.0727596271.

The spelling of 261006257 in words is "two hundred sixty-one million, six thousand, two hundred fifty-seven".