75444306661 has 2 divisors, whose sum is σ = 75444306662. Its totient is φ = 75444306660.

The previous prime is 75444306643. The next prime is 75444306667. The reversal of 75444306661 is 16660344457.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42469378561 + 32974928100 = 206081^2 + 181590^2 .

It is a cyclic number.

It is not a de Polignac number, because 75444306661 - 2⁷ = 75444306533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (75444306667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37722153330 + 37722153331.

It is an arithmetic number, because the mean of its divisors is an integer number (37722153331).

Almost surely, 2^75444306661 is an apocalyptic number.

It is an amenable number.

75444306661 is a deficient number, since it is larger than the sum of its proper divisors (1).

75444306661 is an equidigital number, since it uses as much as digits as its factorization.

75444306661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1451520, while the sum is 46.

The spelling of 75444306661 in words is "seventy-five billion, four hundred forty-four million, three hundred six thousand, six hundred sixty-one".