13503781 has 2 divisors, whose sum is σ = 13503782. Its totient is φ = 13503780.

The previous prime is 13503773. The next prime is 13503793. The reversal of 13503781 is 18730531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10458756 + 3045025 = 3234^2 + 1745^2 .

It is an emirp because it is prime and its reverse (18730531) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13503781 - 2³ = 13503773 is a prime.

It is a super-2 number, since 2×13503781² = 364704202591922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13503751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6751890 + 6751891.

It is an arithmetic number, because the mean of its divisors is an integer number (6751891).

Almost surely, 2^13503781 is an apocalyptic number.

It is an amenable number.

13503781 is a deficient number, since it is larger than the sum of its proper divisors (1).

13503781 is an equidigital number, since it uses as much as digits as its factorization.

13503781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 13503781 is about 3674.7491070820. The cubic root of 13503781 is about 238.1323852142.

The spelling of 13503781 in words is "thirteen million, five hundred three thousand, seven hundred eighty-one".