261612402656149 has 2 divisors, whose sum is σ = 261612402656150. Its totient is φ = 261612402656148.

The previous prime is 261612402656107. The next prime is 261612402656219. The reversal of 261612402656149 is 941656204216162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 256613967680625 + 4998434975524 = 16019175^2 + 2235718^2 .

It is a cyclic number.

It is not a de Polignac number, because 261612402656149 - 2¹⁵ = 261612402623381 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261612402656149.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261612402653149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130806201328074 + 130806201328075.

It is an arithmetic number, because the mean of its divisors is an integer number (130806201328075).

Almost surely, 2^{261612402656149} is an apocalyptic number.

It is an amenable number.

261612402656149 is a deficient number, since it is larger than the sum of its proper divisors (1).

261612402656149 is an equidigital number, since it uses as much as digits as its factorization.

261612402656149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7464960, while the sum is 55.

The spelling of 261612402656149 in words is "two hundred sixty-one trillion, six hundred twelve billion, four hundred two million, six hundred fifty-six thousand, one hundred forty-nine".