261646256413123 has 2 divisors, whose sum is σ = 261646256413124. Its totient is φ = 261646256413122.

The previous prime is 261646256413121. The next prime is 261646256413127. The reversal of 261646256413123 is 321314652646162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261646256413123 - 2¹ = 261646256413121 is a prime.

It is a super-2 number, since 2×261646256413123² (a number of 30 digits) contains 22 as substring.

Together with 261646256413121, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (261646256413121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130823128206561 + 130823128206562.

It is an arithmetic number, because the mean of its divisors is an integer number (130823128206562).

Almost surely, 2^{261646256413123} is an apocalyptic number.

261646256413123 is a deficient number, since it is larger than the sum of its proper divisors (1).

261646256413123 is an equidigital number, since it uses as much as digits as its factorization.

261646256413123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7464960, while the sum is 52.

The spelling of 261646256413123 in words is "two hundred sixty-one trillion, six hundred forty-six billion, two hundred fifty-six million, four hundred thirteen thousand, one hundred twenty-three".