261534452164121 has 2 divisors, whose sum is σ = 261534452164122. Its totient is φ = 261534452164120.

The previous prime is 261534452164103. The next prime is 261534452164147. The reversal of 261534452164121 is 121461254435162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 261480704233225 + 53747930896 = 16170365^2 + 231836^2 .

It is a cyclic number.

It is not a de Polignac number, because 261534452164121 - 2⁶ = 261534452164057 is a prime.

It is not a weakly prime, because it can be changed into another prime (261533452164121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130767226082060 + 130767226082061.

It is an arithmetic number, because the mean of its divisors is an integer number (130767226082061).

Almost surely, 2^{261534452164121} is an apocalyptic number.

It is an amenable number.

261534452164121 is a deficient number, since it is larger than the sum of its proper divisors (1).

261534452164121 is an equidigital number, since it uses as much as digits as its factorization.

261534452164121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1382400, while the sum is 47.

The spelling of 261534452164121 in words is "two hundred sixty-one trillion, five hundred thirty-four billion, four hundred fifty-two million, one hundred sixty-four thousand, one hundred twenty-one".