43555240661 has 2 divisors, whose sum is σ = 43555240662. Its totient is φ = 43555240660.

The previous prime is 43555240649. The next prime is 43555240667. The reversal of 43555240661 is 16604255534.

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., 43027619761 + 527620900 = 207431^2 + 22970^2 .

It is a cyclic number.

It is not a de Polignac number, because 43555240661 - 2¹⁴ = 43555224277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43555240667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21777620330 + 21777620331.

It is an arithmetic number, because the mean of its divisors is an integer number (21777620331).

Almost surely, 2^43555240661 is an apocalyptic number.

It is an amenable number.

43555240661 is a deficient number, since it is larger than the sum of its proper divisors (1).

43555240661 is an equidigital number, since it uses as much as digits as its factorization.

43555240661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432000, while the sum is 41.

The spelling of 43555240661 in words is "forty-three billion, five hundred fifty-five million, two hundred forty thousand, six hundred sixty-one".