143809681 has 4 divisors (see below), whose sum is σ = 152269092. Its totient is φ = 135350272.

The previous prime is 143809669. The next prime is 143809703. The reversal of 143809681 is 186908341.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186908341 = 193 ⋅968437.

It can be written as a sum of positive squares in 2 ways, for example, as 110355025 + 33454656 = 10505^2 + 5784^2 .

It is a cyclic number.

It is not a de Polignac number, because 143809681 - 2⁷ = 143809553 is a prime.

It is a super-2 number, since 2×143809681² = 41362448698643522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (143806681) 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 in 3 ways as a sum of consecutive naturals, for example, 4229680 + ... + 4229713.

It is an arithmetic number, because the mean of its divisors is an integer number (38067273).

Almost surely, 2^143809681 is an apocalyptic number.

It is an amenable number.

143809681 is a deficient number, since it is larger than the sum of its proper divisors (8459411).

143809681 is an equidigital number, since it uses as much as digits as its factorization.

143809681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8459410.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 143809681 is about 11992.0674197571. The cubic root of 143809681 is about 523.9172618137.

The spelling of 143809681 in words is "one hundred forty-three million, eight hundred nine thousand, six hundred eighty-one".