43621399 has 2 divisors, whose sum is σ = 43621400. Its totient is φ = 43621398.

The previous prime is 43621379. The next prime is 43621429. The reversal of 43621399 is 99312634.

43621399 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 43621399 - 2⁹ = 43620887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43621339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21810699 + 21810700.

It is an arithmetic number, because the mean of its divisors is an integer number (21810700).

Almost surely, 2^43621399 is an apocalyptic number.

43621399 is a deficient number, since it is larger than the sum of its proper divisors (1).

43621399 is an equidigital number, since it uses as much as digits as its factorization.

43621399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 37.

The square root of 43621399 is about 6604.6498014656. The cubic root of 43621399 is about 352.0193445593.

The spelling of 43621399 in words is "forty-three million, six hundred twenty-one thousand, three hundred ninety-nine".