19765780128 has 144 divisors (see below), whose sum is σ = 56903648256. Its totient is φ = 6507648000.

The previous prime is 19765780127. The next prime is 19765780129. The reversal of 19765780128 is 82108756791.

It is an interprime number because it is at equal distance from previous prime (19765780127) and next prime (19765780129).

It is a tau number, because it is divible by the number of its divisors (144).

It is not an unprimeable number, because it can be changed into a prime (19765780121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9179500 + ... + 9181652.

It is an arithmetic number, because the mean of its divisors is an integer number (395164224).

Almost surely, 2^19765780128 is an apocalyptic number.

19765780128 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19765780128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28451824128).

19765780128 is an abundant number, since it is smaller than the sum of its proper divisors (37137868128).

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

19765780128 is a wasteful number, since it uses less digits than its factorization.

19765780128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2547 (or 2536 counting only the distinct ones).

The product of its (nonzero) digits is 1693440, while the sum is 54.

The spelling of 19765780128 in words is "nineteen billion, seven hundred sixty-five million, seven hundred eighty thousand, one hundred twenty-eight".