3505681 has 2 divisors, whose sum is σ = 3505682. Its totient is φ = 3505680.

The previous prime is 3505673. The next prime is 3505699. The reversal of 3505681 is 1865053.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2005056 + 1500625 = 1416^2 + 1225^2 .

It is a cyclic number.

It is not a de Polignac number, because 3505681 - 2³ = 3505673 is a prime.

It is a super-2 number, since 2×3505681² = 24579598547522, which contains 22 as substring.

3505681 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (3505631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1752840 + 1752841.

It is an arithmetic number, because the mean of its divisors is an integer number (1752841).

Almost surely, 2^3505681 is an apocalyptic number.

It is an amenable number.

3505681 is a deficient number, since it is larger than the sum of its proper divisors (1).

3505681 is an equidigital number, since it uses as much as digits as its factorization.

3505681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 3505681 is about 1872.3463888928. The cubic root of 3505681 is about 151.9115511501.

It can be divided in two parts, 3505 and 681, that added together give a triangular number (4186 = T₉₁).

The spelling of 3505681 in words is "three million, five hundred five thousand, six hundred eighty-one".