43145681 has 4 divisors (see below), whose sum is σ = 43395252. Its totient is φ = 42896112.

The previous prime is 43145651. The next prime is 43145689. The reversal of 43145681 is 18654134.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 33535681 + 9610000 = 5791^2 + 3100^2 .

It is a cyclic number.

It is not a de Polignac number, because 43145681 - 2⁶ = 43145617 is a prime.

It is a super-2 number, since 2×43145681² = 3723099577907522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43145689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124526 + ... + 124871.

It is an arithmetic number, because the mean of its divisors is an integer number (10848813).

Almost surely, 2^43145681 is an apocalyptic number.

It is an amenable number.

43145681 is a deficient number, since it is larger than the sum of its proper divisors (249571).

43145681 is a wasteful number, since it uses less digits than its factorization.

43145681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249570.

The product of its digits is 11520, while the sum is 32.

The square root of 43145681 is about 6568.5372039747. The cubic root of 43145681 is about 350.7350023485.

The spelling of 43145681 in words is "forty-three million, one hundred forty-five thousand, six hundred eighty-one".