43516721 has 2 divisors, whose sum is σ = 43516722. Its totient is φ = 43516720.

The previous prime is 43516663. The next prime is 43516727. The reversal of 43516721 is 12761534.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42393121 + 1123600 = 6511^2 + 1060^2 .

It is a cyclic number.

It is not a de Polignac number, because 43516721 - 2¹⁰ = 43515697 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (43516727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21758360 + 21758361.

It is an arithmetic number, because the mean of its divisors is an integer number (21758361).

Almost surely, 2^43516721 is an apocalyptic number.

It is an amenable number.

43516721 is a deficient number, since it is larger than the sum of its proper divisors (1).

43516721 is an equidigital number, since it uses as much as digits as its factorization.

43516721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 29.

The square root of 43516721 is about 6596.7204730836. The cubic root of 43516721 is about 351.7375394794.

The spelling of 43516721 in words is "forty-three million, five hundred sixteen thousand, seven hundred twenty-one".