19268278656857 has 2 divisors, whose sum is σ = 19268278656858. Its totient is φ = 19268278656856.

The previous prime is 19268278656853. The next prime is 19268278656859. The reversal of 19268278656857 is 75865687286291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16826822406601 + 2441456250256 = 4102051^2 + 1562516^2 .

It is a cyclic number.

It is not a de Polignac number, because 19268278656857 - 2² = 19268278656853 is a prime.

Together with 19268278656859, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19268278656853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9634139328428 + 9634139328429.

It is an arithmetic number, because the mean of its divisors is an integer number (9634139328429).

Almost surely, 2^{19268278656857} is an apocalyptic number.

It is an amenable number.

19268278656857 is a deficient number, since it is larger than the sum of its proper divisors (1).

19268278656857 is an equidigital number, since it uses as much as digits as its factorization.

19268278656857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4877107200, while the sum is 80.

The spelling of 19268278656857 in words is "nineteen trillion, two hundred sixty-eight billion, two hundred seventy-eight million, six hundred fifty-six thousand, eight hundred fifty-seven".