17139784561 has 9 divisors (see below), whose sum is σ = 17346322443. Its totient is φ = 16935681840.

The previous prime is 17139784559. The next prime is 17139784579. The reversal of 17139784561 is 16548793171.

The square root of 17139784561 is 130919.

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

It can be written as a sum of positive squares in only one way, i.e., 3291202161 + 13848582400 = 57369^2 + 117680^2 .

It is not a de Polignac number, because 17139784561 - 2¹ = 17139784559 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 17139784499 and 17139784508.

It is not an unprimeable number, because it can be changed into a prime (17139785561) 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, 11651056 + ... + 11652526.

Almost surely, 2^17139784561 is an apocalyptic number.

17139784561 is the 130919-th square number.

17139784561 is the 65460-th centered octagonal number.

It is an amenable number.

17139784561 is a deficient number, since it is larger than the sum of its proper divisors (206537882).

17139784561 is an frugal number, since it uses more digits than its factorization.

17139784561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3120 (or 1560 counting only the distinct ones).

The product of its digits is 1270080, while the sum is 52.

The spelling of 17139784561 in words is "seventeen billion, one hundred thirty-nine million, seven hundred eighty-four thousand, five hundred sixty-one".