42856128391 has 2 divisors, whose sum is σ = 42856128392. Its totient is φ = 42856128390.

The previous prime is 42856128353. The next prime is 42856128397. The reversal of 42856128391 is 19382165824.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42856128391 - 2⁹ = 42856127879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42856128397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21428064195 + 21428064196.

It is an arithmetic number, because the mean of its divisors is an integer number (21428064196).

Almost surely, 2^42856128391 is an apocalyptic number.

42856128391 is a deficient number, since it is larger than the sum of its proper divisors (1).

42856128391 is an equidigital number, since it uses as much as digits as its factorization.

42856128391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 829440, while the sum is 49.

The spelling of 42856128391 in words is "forty-two billion, eight hundred fifty-six million, one hundred twenty-eight thousand, three hundred ninety-one".