43780879657 has 2 divisors, whose sum is σ = 43780879658. Its totient is φ = 43780879656.

The previous prime is 43780879631. The next prime is 43780879663. The reversal of 43780879657 is 75697808734.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29480546601 + 14300333056 = 171699^2 + 119584^2 .

It is a cyclic number.

It is not a de Polignac number, because 43780879657 - 2¹⁹ = 43780355369 is a prime.

It is not a weakly prime, because it can be changed into another prime (43780879607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21890439828 + 21890439829.

It is an arithmetic number, because the mean of its divisors is an integer number (21890439829).

Almost surely, 2^43780879657 is an apocalyptic number.

It is an amenable number.

43780879657 is a deficient number, since it is larger than the sum of its proper divisors (1).

43780879657 is an equidigital number, since it uses as much as digits as its factorization.

43780879657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 71124480, while the sum is 64.

The spelling of 43780879657 in words is "forty-three billion, seven hundred eighty million, eight hundred seventy-nine thousand, six hundred fifty-seven".