43307981 has 2 divisors, whose sum is σ = 43307982. Its totient is φ = 43307980.

The previous prime is 43307977. The next prime is 43307983. The reversal of 43307981 is 18970334.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42367081 + 940900 = 6509^2 + 970^2 .

It is a cyclic number.

It is not a de Polignac number, because 43307981 - 2² = 43307977 is a prime.

It is a super-2 number, since 2×43307981² = 3751162436592722, which contains 22 as substring.

Together with 43307983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43307983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21653990 + 21653991.

It is an arithmetic number, because the mean of its divisors is an integer number (21653991).

Almost surely, 2^43307981 is an apocalyptic number.

It is an amenable number.

43307981 is a deficient number, since it is larger than the sum of its proper divisors (1).

43307981 is an equidigital number, since it uses as much as digits as its factorization.

43307981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 43307981 is about 6580.8799563584. The cubic root of 43307981 is about 351.1742356736.

The spelling of 43307981 in words is "forty-three million, three hundred seven thousand, nine hundred eighty-one".