66717643 has 2 divisors, whose sum is σ = 66717644. Its totient is φ = 66717642.

The previous prime is 66717601. The next prime is 66717647. The reversal of 66717643 is 34671766.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66717643 - 2¹³ = 66709451 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66717596 and 66717605.

It is not a weakly prime, because it can be changed into another prime (66717647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33358821 + 33358822.

It is an arithmetic number, because the mean of its divisors is an integer number (33358822).

Almost surely, 2^66717643 is an apocalyptic number.

66717643 is a deficient number, since it is larger than the sum of its proper divisors (1).

66717643 is an equidigital number, since it uses as much as digits as its factorization.

66717643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 40.

The square root of 66717643 is about 8168.0868629074. The cubic root of 66717643 is about 405.5834561596.

The spelling of 66717643 in words is "sixty-six million, seven hundred seventeen thousand, six hundred forty-three".