19489021850957 has 2 divisors, whose sum is σ = 19489021850958. Its totient is φ = 19489021850956.

The previous prime is 19489021850933. The next prime is 19489021851041. The reversal of 19489021850957 is 75905812098491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15965250887716 + 3523770963241 = 3995654^2 + 1877171^2 .

It is a cyclic number.

It is not a de Polignac number, because 19489021850957 - 2²⁶ = 19488954742093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19489021850057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9744510925478 + 9744510925479.

It is an arithmetic number, because the mean of its divisors is an integer number (9744510925479).

Almost surely, 2^{19489021850957} is an apocalyptic number.

It is an amenable number.

19489021850957 is a deficient number, since it is larger than the sum of its proper divisors (1).

19489021850957 is an equidigital number, since it uses as much as digits as its factorization.

19489021850957 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 65318400, while the sum is 68.

The spelling of 19489021850957 in words is "nineteen trillion, four hundred eighty-nine billion, twenty-one million, eight hundred fifty thousand, nine hundred fifty-seven".