43812221 has 2 divisors, whose sum is σ = 43812222. Its totient is φ = 43812220.

The previous prime is 43812211. The next prime is 43812287. The reversal of 43812221 is 12221834.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40819321 + 2992900 = 6389^2 + 1730^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43812221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43812211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21906110 + 21906111.

It is an arithmetic number, because the mean of its divisors is an integer number (21906111).

Almost surely, 2^43812221 is an apocalyptic number.

It is an amenable number.

43812221 is a deficient number, since it is larger than the sum of its proper divisors (1).

43812221 is an equidigital number, since it uses as much as digits as its factorization.

43812221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 768, while the sum is 23.

The square root of 43812221 is about 6619.0800720342. The cubic root of 43812221 is about 352.5319012759.

The spelling of 43812221 in words is "forty-three million, eight hundred twelve thousand, two hundred twenty-one".