19778258667 has 4 divisors (see below), whose sum is σ = 26371011560. Its totient is φ = 13185505776.

The previous prime is 19778258663. The next prime is 19778258681. The reversal of 19778258667 is 76685287791.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 19778258667 - 2² = 19778258663 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19778258598 and 19778258607.

It is not an unprimeable number, because it can be changed into a prime (19778258663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3296376442 + ... + 3296376447.

It is an arithmetic number, because the mean of its divisors is an integer number (6592752890).

Almost surely, 2^19778258667 is an apocalyptic number.

19778258667 is a deficient number, since it is larger than the sum of its proper divisors (6592752893).

19778258667 is an equidigital number, since it uses as much as digits as its factorization.

19778258667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6592752892.

The product of its digits is 71124480, while the sum is 66.

The spelling of 19778258667 in words is "nineteen billion, seven hundred seventy-eight million, two hundred fifty-eight thousand, six hundred sixty-seven".