19789374642857 has 2 divisors, whose sum is σ = 19789374642858. Its totient is φ = 19789374642856.

The previous prime is 19789374642781. The next prime is 19789374642949. The reversal of 19789374642857 is 75824647398791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17803766741401 + 1985607901456 = 4219451^2 + 1409116^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19789374642857 is a prime.

It is a super-2 number, since 2×19789374642857² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19789371642857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9894687321428 + 9894687321429.

It is an arithmetic number, because the mean of its divisors is an integer number (9894687321429).

Almost surely, 2^{19789374642857} is an apocalyptic number.

It is an amenable number.

19789374642857 is a deficient number, since it is larger than the sum of its proper divisors (1).

19789374642857 is an equidigital number, since it uses as much as digits as its factorization.

19789374642857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5120962560, while the sum is 80.

The spelling of 19789374642857 in words is "nineteen trillion, seven hundred eighty-nine billion, three hundred seventy-four million, six hundred forty-two thousand, eight hundred fifty-seven".