43999913 has 2 divisors, whose sum is σ = 43999914. Its totient is φ = 43999912.

The previous prime is 43999903. The next prime is 43999957. The reversal of 43999913 is 31999934.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40806544 + 3193369 = 6388^2 + 1787^2 .

It is a cyclic number.

It is not a de Polignac number, because 43999913 - 2¹² = 43995817 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (43999903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21999956 + 21999957.

It is an arithmetic number, because the mean of its divisors is an integer number (21999957).

Almost surely, 2^43999913 is an apocalyptic number.

It is an amenable number.

43999913 is a deficient number, since it is larger than the sum of its proper divisors (1).

43999913 is an equidigital number, since it uses as much as digits as its factorization.

43999913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 236196, while the sum is 47.

The square root of 43999913 is about 6633.2430228358. The cubic root of 43999913 is about 353.0346008504.

The spelling of 43999913 in words is "forty-three million, nine hundred ninety-nine thousand, nine hundred thirteen".