66677777 has 2 divisors, whose sum is σ = 66677778. Its totient is φ = 66677776.

The previous prime is 66677773. The next prime is 66677789. The reversal of 66677777 is 77777666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47458321 + 19219456 = 6889^2 + 4384^2 .

It is a cyclic number.

It is not a de Polignac number, because 66677777 - 2² = 66677773 is a prime.

It is a super-3 number, since 3×66677777³ (a number of 24 digits) contains 333 as substring.

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is not a weakly prime, because it can be changed into another prime (66677773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33338888 + 33338889.

It is an arithmetic number, because the mean of its divisors is an integer number (33338889).

Almost surely, 2^66677777 is an apocalyptic number.

It is an amenable number.

66677777 is a deficient number, since it is larger than the sum of its proper divisors (1).

66677777 is an equidigital number, since it uses as much as digits as its factorization.

66677777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3630312, while the sum is 53.

The square root of 66677777 is about 8165.6461471215. The cubic root of 66677777 is about 405.5026568842.

The spelling of 66677777 in words is "sixty-six million, six hundred seventy-seven thousand, seven hundred seventy-seven".