43287821 has 2 divisors, whose sum is σ = 43287822. Its totient is φ = 43287820.

The previous prime is 43287793. The next prime is 43287847. The reversal of 43287821 is 12878234.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42432196 + 855625 = 6514^2 + 925^2 .

It is a cyclic number.

It is not a de Polignac number, because 43287821 - 2¹⁸ = 43025677 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43287851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21643910 + 21643911.

It is an arithmetic number, because the mean of its divisors is an integer number (21643911).

Almost surely, 2^43287821 is an apocalyptic number.

It is an amenable number.

43287821 is a deficient number, since it is larger than the sum of its proper divisors (1).

43287821 is an equidigital number, since it uses as much as digits as its factorization.

43287821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21504, while the sum is 35.

The square root of 43287821 is about 6579.3480680080. The cubic root of 43287821 is about 351.1197363161.

The spelling of 43287821 in words is "forty-three million, two hundred eighty-seven thousand, eight hundred twenty-one".