1361018781 has 20 divisors (see below), whose sum is σ = 2035850652. Its totient is φ = 906130368.

The previous prime is 1361018779. The next prime is 1361018819. The reversal of 1361018781 is 1878101631.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 81812025 + 1279206756 = 9045^2 + 35766^2 .

It is not a de Polignac number, because 1361018781 - 2¹ = 1361018779 is a prime.

It is a super-3 number, since 3×1361018781³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1361018731) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 51745 + ... + 73481.

Almost surely, 2^1361018781 is an apocalyptic number.

It is an amenable number.

1361018781 is a deficient number, since it is larger than the sum of its proper divisors (674831871).

1361018781 is an equidigital number, since it uses as much as digits as its factorization.

1361018781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22522 (or 22513 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 1361018781 is about 36891.9880326339. The cubic root of 1361018781 is about 1108.2082341904.

The spelling of 1361018781 in words is "one billion, three hundred sixty-one million, eighteen thousand, seven hundred eighty-one".