43126991849 has 4 divisors (see below), whose sum is σ = 43127431236. Its totient is φ = 43126552464.

The previous prime is 43126991839. The next prime is 43126991911. The reversal of 43126991849 is 94819962134.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 94819962134 = 2 ⋅47409981067.

It can be written as a sum of positive squares in 2 ways, for example, as 9964032400 + 33162959449 = 99820^2 + 182107^2 .

It is a cyclic number.

It is not a de Polignac number, because 43126991849 - 2⁴ = 43126991833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 43126991794 and 43126991803.

It is not an unprimeable number, because it can be changed into a prime (43126991839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2327 + ... + 293699.

It is an arithmetic number, because the mean of its divisors is an integer number (10781857809).

Almost surely, 2^43126991849 is an apocalyptic number.

It is an amenable number.

43126991849 is a deficient number, since it is larger than the sum of its proper divisors (439387).

43126991849 is a wasteful number, since it uses less digits than its factorization.

43126991849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439386.

The product of its digits is 3359232, while the sum is 56.

The spelling of 43126991849 in words is "forty-three billion, one hundred twenty-six million, nine hundred ninety-one thousand, eight hundred forty-nine".