1781042386249 has 27 divisors (see below), whose sum is σ = 2098000670727. Its totient is φ = 1507558293024.

The previous prime is 1781042386243. The next prime is 1781042386267. The reversal of 1781042386249 is 9426832401871.

The square root of 1781042386249 is 1334557.

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., 837362255625 + 943680130624 = 915075^2 + 971432^2 .

It is not a de Polignac number, because 1781042386249 - 2⁷ = 1781042386121 is a prime.

It is a super-2 number, since 2×1781042386249² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1781042386249.

It is not an unprimeable number, because it can be changed into a prime (1781042386243) 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, 775376469 + ... + 775378765.

Almost surely, 2^{1781042386249} is an apocalyptic number.

1781042386249 is the 1334557-th square number.

1781042386249 is the 667279-th centered octagonal number.

It is an amenable number.

1781042386249 is a deficient number, since it is larger than the sum of its proper divisors (316958284478).

1781042386249 is an frugal number, since it uses more digits than its factorization.

1781042386249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4774 (or 2387 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 55.

The spelling of 1781042386249 in words is "one trillion, seven hundred eighty-one billion, forty-two million, three hundred eighty-six thousand, two hundred forty-nine".