261440637356741 has 2 divisors, whose sum is σ = 261440637356742. Its totient is φ = 261440637356740.

The previous prime is 261440637356693. The next prime is 261440637356761. The reversal of 261440637356741 is 147653736044162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188824589891716 + 72616047465025 = 13741346^2 + 8521505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261440637356741 is a prime.

It is a super-2 number, since 2×261440637356741² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261440637356761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130720318678370 + 130720318678371.

It is an arithmetic number, because the mean of its divisors is an integer number (130720318678371).

Almost surely, 2^{261440637356741} is an apocalyptic number.

It is an amenable number.

261440637356741 is a deficient number, since it is larger than the sum of its proper divisors (1).

261440637356741 is an equidigital number, since it uses as much as digits as its factorization.

261440637356741 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60963840, while the sum is 59.

The spelling of 261440637356741 in words is "two hundred sixty-one trillion, four hundred forty billion, six hundred thirty-seven million, three hundred fifty-six thousand, seven hundred forty-one".