43975666991 has 4 divisors (see below), whose sum is σ = 46290175800. Its totient is φ = 41661158184.

The previous prime is 43975666967. The next prime is 43975667003. The reversal of 43975666991 is 19966657934.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 43975666991 - 2³⁴ = 26795797807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43975666901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1157254376 + ... + 1157254413.

It is an arithmetic number, because the mean of its divisors is an integer number (11572543950).

Almost surely, 2^43975666991 is an apocalyptic number.

43975666991 is a deficient number, since it is larger than the sum of its proper divisors (2314508809).

43975666991 is a wasteful number, since it uses less digits than its factorization.

43975666991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2314508808.

The product of its digits is 66134880, while the sum is 65.

The spelling of 43975666991 in words is "forty-three billion, nine hundred seventy-five million, six hundred sixty-six thousand, nine hundred ninety-one".