43216891 has 2 divisors, whose sum is σ = 43216892. Its totient is φ = 43216890.

The previous prime is 43216879. The next prime is 43216897. The reversal of 43216891 is 19861234.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 43216891 - 2¹⁵ = 43184123 is a prime.

It is equal to p_2616883 and since 43216891 and 2616883 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (43216897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21608445 + 21608446.

It is an arithmetic number, because the mean of its divisors is an integer number (21608446).

Almost surely, 2^43216891 is an apocalyptic number.

43216891 is a deficient number, since it is larger than the sum of its proper divisors (1).

43216891 is an equidigital number, since it uses as much as digits as its factorization.

43216891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 34.

The square root of 43216891 is about 6573.9555063903. The cubic root of 43216891 is about 350.9278537226.

The spelling of 43216891 in words is "forty-three million, two hundred sixteen thousand, eight hundred ninety-one".