19863128635249 has 27 divisors (see below), whose sum is σ = 20679734187489. Its totient is φ = 19077986316480.

The previous prime is 19863128635237. The next prime is 19863128635289. The reversal of 19863128635249 is 94253682136891.

The square root of 19863128635249 is 4456807.

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

It can be written as a sum of positive squares in 4 ways, for example, as 7874000784225 + 11989127851024 = 2806065^2 + 3462532^2 .

It is not a de Polignac number, because 19863128635249 - 2⁷ = 19863128635121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19863128635289) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 40454436894 + ... + 40454437384.

Almost surely, 2^{19863128635249} is an apocalyptic number.

19863128635249 is the 4456807-th square number.

19863128635249 is the 2228404-th centered octagonal number.

It is an amenable number.

19863128635249 is a deficient number, since it is larger than the sum of its proper divisors (816605552240).

19863128635249 is an frugal number, since it uses more digits than its factorization.

19863128635249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1666 (or 833 counting only the distinct ones).

The product of its digits is 134369280, while the sum is 67.

The spelling of 19863128635249 in words is "nineteen trillion, eight hundred sixty-three billion, one hundred twenty-eight million, six hundred thirty-five thousand, two hundred forty-nine".