19549564977121 has 9 divisors (see below), whose sum is σ = 19568812959633. Its totient is φ = 19530335921460.

The previous prime is 19549564977109. The next prime is 19549564977127. The reversal of 19549564977121 is 12177946594591.

The square root of 19549564977121 is 4421489.

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

It is a de Polignac number, because none of the positive numbers 2^k-19549564977121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19549564977127) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 7158389326 + ... + 7158392056.

Almost surely, 2^{19549564977121} is an apocalyptic number.

19549564977121 is the 4421489-th square number.

19549564977121 is the 2210745-th centered octagonal number.

It is an amenable number.

19549564977121 is a deficient number, since it is larger than the sum of its proper divisors (19247982512).

19549564977121 is an frugal number, since it uses more digits than its factorization.

19549564977121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8700 (or 4350 counting only the distinct ones).

The product of its digits is 171460800, while the sum is 70.

The spelling of 19549564977121 in words is "nineteen trillion, five hundred forty-nine billion, five hundred sixty-four million, nine hundred seventy-seven thousand, one hundred twenty-one".