261415678291 has 2 divisors, whose sum is σ = 261415678292. Its totient is φ = 261415678290.

The previous prime is 261415678289. The next prime is 261415678339. The reversal of 261415678291 is 192876514162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261415678291 - 2¹ = 261415678289 is a prime.

Together with 261415678289, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (261415678241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130707839145 + 130707839146.

It is an arithmetic number, because the mean of its divisors is an integer number (130707839146).

Almost surely, 2^261415678291 is an apocalyptic number.

261415678291 is a deficient number, since it is larger than the sum of its proper divisors (1).

261415678291 is an equidigital number, since it uses as much as digits as its factorization.

261415678291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1451520, while the sum is 52.

The spelling of 261415678291 in words is "two hundred sixty-one billion, four hundred fifteen million, six hundred seventy-eight thousand, two hundred ninety-one".