19755145809 has 135 divisors (see below), whose sum is σ = 36260087787. Its totient is φ = 10686525696.

The previous prime is 19755145801. The next prime is 19755145819. The reversal of 19755145809 is 90854155791.

It is a happy number.

The square root of 19755145809 is 140553.

It is a perfect power (a square), and thus also a powerful number.

19755145809 is a `hidden beast` number, since 1 + 9 + 7 + 5 + 51 + 4 + 580 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 8870814225 + 10884331584 = 94185^2 + 104328^2 .

It is not a de Polignac number, because 19755145809 - 2³ = 19755145801 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19755145801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 203661249 + ... + 203661345.

Almost surely, 2^19755145809 is an apocalyptic number.

19755145809 is the 140553-rd square number.

19755145809 is the 70277-th centered octagonal number.

It is an amenable number.

19755145809 is a deficient number, since it is larger than the sum of its proper divisors (16504941978).

19755145809 is an frugal number, since it uses more digits than its factorization.

19755145809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 2268000, while the sum is 54.

The spelling of 19755145809 in words is "nineteen billion, seven hundred fifty-five million, one hundred forty-five thousand, eight hundred nine".