19539326149561 has 27 divisors (see below), whose sum is σ = 20880736032069. Its totient is φ = 18281392773912.

The previous prime is 19539326149547. The next prime is 19539326149571. The reversal of 19539326149561 is 16594162393591.

The square root of 19539326149561 is 4420331.

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

It is not a de Polignac number, because 19539326149561 - 2²⁹ = 19538789278649 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 19539326149493 and 19539326149502.

It is not an unprimeable number, because it can be changed into a prime (19539326149571) 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, 6970860586 + ... + 6970863388.

Almost surely, 2^{19539326149561} is an apocalyptic number.

19539326149561 is the 4420331-st square number.

19539326149561 is the 2210166-th centered octagonal number.

It is an amenable number.

19539326149561 is a deficient number, since it is larger than the sum of its proper divisors (1341409882508).

19539326149561 is an frugal number, since it uses more digits than its factorization.

19539326149561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5810 (or 2905 counting only the distinct ones).

The product of its digits is 47239200, while the sum is 64.

The spelling of 19539326149561 in words is "nineteen trillion, five hundred thirty-nine billion, three hundred twenty-six million, one hundred forty-nine thousand, five hundred sixty-one".