43840397 has 2 divisors, whose sum is σ = 43840398. Its totient is φ = 43840396.

The previous prime is 43840393. The next prime is 43840403. The reversal of 43840397 is 79304834.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42954916 + 885481 = 6554^2 + 941^2 .

It is a cyclic number.

It is not a de Polignac number, because 43840397 - 2² = 43840393 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 43840397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43840393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21920198 + 21920199.

It is an arithmetic number, because the mean of its divisors is an integer number (21920199).

Almost surely, 2^43840397 is an apocalyptic number.

It is an amenable number.

43840397 is a deficient number, since it is larger than the sum of its proper divisors (1).

43840397 is an equidigital number, since it uses as much as digits as its factorization.

43840397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 38.

The square root of 43840397 is about 6621.2081223898. The cubic root of 43840397 is about 352.6074571373.

The spelling of 43840397 in words is "forty-three million, eight hundred forty thousand, three hundred ninety-seven".