19891706468 has 6 divisors (see below), whose sum is σ = 34810486326. Its totient is φ = 9945853232.

The previous prime is 19891706437. The next prime is 19891706479. The reversal of 19891706468 is 86460719891.

It can be written as a sum of positive squares in only one way, i.e., 19360496164 + 531210304 = 139142^2 + 23048^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2486463305 + ... + 2486463312.

It is an arithmetic number, because the mean of its divisors is an integer number (5801747721).

Almost surely, 2^19891706468 is an apocalyptic number.

It is an amenable number.

19891706468 is a deficient number, since it is larger than the sum of its proper divisors (14918779858).

19891706468 is a wasteful number, since it uses less digits than its factorization.

19891706468 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4972926621 (or 4972926619 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 59.

The spelling of 19891706468 in words is "nineteen billion, eight hundred ninety-one million, seven hundred six thousand, four hundred sixty-eight".