43972979221 has 2 divisors, whose sum is σ = 43972979222. Its totient is φ = 43972979220.

The previous prime is 43972979191. The next prime is 43972979227. The reversal of 43972979221 is 12297927934.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36261680625 + 7711298596 = 190425^2 + 87814^2 .

It is a cyclic number.

It is not a de Polignac number, because 43972979221 - 2²⁷ = 43838761493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43972979227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21986489610 + 21986489611.

It is an arithmetic number, because the mean of its divisors is an integer number (21986489611).

Almost surely, 2^43972979221 is an apocalyptic number.

It is an amenable number.

43972979221 is a deficient number, since it is larger than the sum of its proper divisors (1).

43972979221 is an equidigital number, since it uses as much as digits as its factorization.

43972979221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3429216, while the sum is 55.

The spelling of 43972979221 in words is "forty-three billion, nine hundred seventy-two million, nine hundred seventy-nine thousand, two hundred twenty-one".