103815781 has 2 divisors, whose sum is σ = 103815782. Its totient is φ = 103815780.

The previous prime is 103815773. The next prime is 103815793. The reversal of 103815781 is 187518301.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 103530625 + 285156 = 10175^2 + 534^2 .

It is a cyclic number.

It is not a de Polignac number, because 103815781 - 2³ = 103815773 is a prime.

It is a super-2 number, since 2×103815781² = 21555432769279922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (103815581) 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, 51907890 + 51907891.

It is an arithmetic number, because the mean of its divisors is an integer number (51907891).

Almost surely, 2^103815781 is an apocalyptic number.

It is an amenable number.

103815781 is a deficient number, since it is larger than the sum of its proper divisors (1).

103815781 is an equidigital number, since it uses as much as digits as its factorization.

103815781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 34.

The square root of 103815781 is about 10189.0029443513. The cubic root of 103815781 is about 469.9891064323.

The spelling of 103815781 in words is "one hundred three million, eight hundred fifteen thousand, seven hundred eighty-one".