66707777 has 2 divisors, whose sum is σ = 66707778. Its totient is φ = 66707776.

The previous prime is 66707741. The next prime is 66707789. The reversal of 66707777 is 77770766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42981136 + 23726641 = 6556^2 + 4871^2 .

It is a cyclic number.

It is not a de Polignac number, because 66707777 - 2¹⁰ = 66706753 is a prime.

It is not a weakly prime, because it can be changed into another prime (66707737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33353888 + 33353889.

It is an arithmetic number, because the mean of its divisors is an integer number (33353889).

Almost surely, 2^66707777 is an apocalyptic number.

It is an amenable number.

66707777 is a deficient number, since it is larger than the sum of its proper divisors (1).

66707777 is an equidigital number, since it uses as much as digits as its factorization.

66707777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 605052, while the sum is 47.

The square root of 66707777 is about 8167.4829047877. The cubic root of 66707777 is about 405.5634630291.

The spelling of 66707777 in words is "sixty-six million, seven hundred seven thousand, seven hundred seventy-seven".