19880915778 has 64 divisors (see below), whose sum is σ = 46866263040. Its totient is φ = 6225465600.

The previous prime is 19880915777. The next prime is 19880915783. The reversal of 19880915778 is 87751908891.

It is not an unprimeable number, because it can be changed into a prime (19880915777) 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 31 ways as a sum of consecutive naturals, for example, 476623 + ... + 516653.

It is an arithmetic number, because the mean of its divisors is an integer number (732285360).

Almost surely, 2^19880915778 is an apocalyptic number.

19880915778 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19880915778, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23433131520).

19880915778 is an abundant number, since it is smaller than the sum of its proper divisors (26985347262).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19880915778 is a wasteful number, since it uses less digits than its factorization.

19880915778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40600 (or 40594 counting only the distinct ones).

The product of its (nonzero) digits is 10160640, while the sum is 63.

The spelling of 19880915778 in words is "nineteen billion, eight hundred eighty million, nine hundred fifteen thousand, seven hundred seventy-eight".