3505705681 has 3 divisors (see below), whose sum is σ = 3505764891. Its totient is φ = 3505646472.

The previous prime is 3505705667. The next prime is 3505705729. The reversal of 3505705681 is 1865075053.

The square root of 3505705681 is 59209.

It is a perfect power (a square), and thus also a powerful number.

3505705681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 2003368081 + 1502337600 = 44759^2 + 38760^2 .

It is not a de Polignac number, because 3505705681 - 2⁹ = 3505705169 is a prime.

It is a super-2 number, since 2×3505705681² = 24579944643591347522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3505705661) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 29605 + ... + 88813.

It is an arithmetic number, because the mean of its divisors is an integer number (1168588297).

Almost surely, 2^3505705681 is an apocalyptic number.

3505705681 is the 59209-th square number.

3505705681 is the 29605-th centered octagonal number.

It is an amenable number.

3505705681 is a deficient number, since it is larger than the sum of its proper divisors (59210).

3505705681 is an frugal number, since it uses more digits than its factorization.

3505705681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118418 (or 59209 counting only the distinct ones).

The product of its (nonzero) digits is 126000, while the sum is 40.

The cubic root of 3505705681 is about 1519.1190764953.

The spelling of 3505705681 in words is "three billion, five hundred five million, seven hundred five thousand, six hundred eighty-one".