1781050013 has 4 divisors (see below), whose sum is σ = 1781384220. Its totient is φ = 1780715808.

The previous prime is 1781050003. The next prime is 1781050021. The reversal of 1781050013 is 3100501871.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 140232964 + 1640817049 = 11842^2 + 40507^2 .

It is a cyclic number.

It is not a de Polignac number, because 1781050013 - 2¹⁴ = 1781033629 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1781050003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158978 + ... + 169811.

It is an arithmetic number, because the mean of its divisors is an integer number (445346055).

Almost surely, 2^1781050013 is an apocalyptic number.

It is an amenable number.

1781050013 is a deficient number, since it is larger than the sum of its proper divisors (334207).

1781050013 is an equidigital number, since it uses as much as digits as its factorization.

1781050013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334206.

The product of its (nonzero) digits is 840, while the sum is 26.

The square root of 1781050013 is about 42202.4882323306. The cubic root of 1781050013 is about 1212.1565287512.

Adding to 1781050013 its reverse (3100501871), we get a palindrome (4881551884).

The spelling of 1781050013 in words is "one billion, seven hundred eighty-one million, fifty thousand, thirteen".