66440771 has 2 divisors, whose sum is σ = 66440772. Its totient is φ = 66440770.

The previous prime is 66440761. The next prime is 66440779. The reversal of 66440771 is 17704466.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66440771 - 2⁶ = 66440707 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (66440779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33220385 + 33220386.

It is an arithmetic number, because the mean of its divisors is an integer number (33220386).

Almost surely, 2^66440771 is an apocalyptic number.

66440771 is a deficient number, since it is larger than the sum of its proper divisors (1).

66440771 is an equidigital number, since it uses as much as digits as its factorization.

66440771 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 35.

The square root of 66440771 is about 8151.1208431724. The cubic root of 66440771 is about 405.0216337578.

The spelling of 66440771 in words is "sixty-six million, four hundred forty thousand, seven hundred seventy-one".