43211921 has 2 divisors, whose sum is σ = 43211922. Its totient is φ = 43211920.

The previous prime is 43211911. The next prime is 43211929. The reversal of 43211921 is 12911234.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25361296 + 17850625 = 5036^2 + 4225^2 .

It is a cyclic number.

It is not a de Polignac number, because 43211921 - 2¹⁰ = 43210897 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (43211929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21605960 + 21605961.

It is an arithmetic number, because the mean of its divisors is an integer number (21605961).

Almost surely, 2^43211921 is an apocalyptic number.

It is an amenable number.

43211921 is a deficient number, since it is larger than the sum of its proper divisors (1).

43211921 is an equidigital number, since it uses as much as digits as its factorization.

43211921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 23.

The square root of 43211921 is about 6573.5774887043. The cubic root of 43211921 is about 350.9144008167.

The spelling of 43211921 in words is "forty-three million, two hundred eleven thousand, nine hundred twenty-one".