66747749 has 2 divisors, whose sum is σ = 66747750. Its totient is φ = 66747748.

The previous prime is 66747727. The next prime is 66747757. The reversal of 66747749 is 94774766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36990724 + 29757025 = 6082^2 + 5455^2 .

It is a cyclic number.

It is not a de Polignac number, because 66747749 - 2²⁰ = 65699173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66747697 and 66747706.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66747799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33373874 + 33373875.

It is an arithmetic number, because the mean of its divisors is an integer number (33373875).

Almost surely, 2^66747749 is an apocalyptic number.

It is an amenable number.

66747749 is a deficient number, since it is larger than the sum of its proper divisors (1).

66747749 is an equidigital number, since it uses as much as digits as its factorization.

66747749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1778112, while the sum is 50.

The square root of 66747749 is about 8169.9295590599. The cubic root of 66747749 is about 405.6444528156.

The spelling of 66747749 in words is "sixty-six million, seven hundred forty-seven thousand, seven hundred forty-nine".