268687949786891 has 2 divisors, whose sum is σ = 268687949786892. Its totient is φ = 268687949786890.

The previous prime is 268687949786819. The next prime is 268687949786897. The reversal of 268687949786891 is 198687949786862.

Together with previous prime (268687949786819) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 268687949786891 - 2⁴² = 264289903275787 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (268687949786897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 134343974893445 + 134343974893446.

It is an arithmetic number, because the mean of its divisors is an integer number (134343974893446).

Almost surely, 2^{268687949786891} is an apocalyptic number.

268687949786891 is a deficient number, since it is larger than the sum of its proper divisors (1).

268687949786891 is an equidigital number, since it uses as much as digits as its factorization.

268687949786891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 252829237248, while the sum is 98.

The spelling of 268687949786891 in words is "two hundred sixty-eight trillion, six hundred eighty-seven billion, nine hundred forty-nine million, seven hundred eighty-six thousand, eight hundred ninety-one".