43489981 has 2 divisors, whose sum is σ = 43489982. Its totient is φ = 43489980.

The previous prime is 43489967. The next prime is 43489991. The reversal of 43489981 is 18998434.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36905625 + 6584356 = 6075^2 + 2566^2 .

It is a cyclic number.

It is not a de Polignac number, because 43489981 - 2⁵ = 43489949 is a prime.

It is a super-2 number, since 2×43489981² = 3782756894760722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43489991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21744990 + 21744991.

It is an arithmetic number, because the mean of its divisors is an integer number (21744991).

Almost surely, 2^43489981 is an apocalyptic number.

It is an amenable number.

43489981 is a deficient number, since it is larger than the sum of its proper divisors (1).

43489981 is an equidigital number, since it uses as much as digits as its factorization.

43489981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 248832, while the sum is 46.

The square root of 43489981 is about 6594.6933969670. The cubic root of 43489981 is about 351.6654799068.

The spelling of 43489981 in words is "forty-three million, four hundred eighty-nine thousand, nine hundred eighty-one".