667426777 has 2 divisors, whose sum is σ = 667426778. Its totient is φ = 667426776.

The previous prime is 667426763. The next prime is 667426789. The reversal of 667426777 is 777624766.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 660541401 + 6885376 = 25701^2 + 2624^2 .

It is a cyclic number.

It is not a de Polignac number, because 667426777 - 2²⁷ = 533209049 is a prime.

It is not a weakly prime, because it can be changed into another prime (667420777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333713388 + 333713389.

It is an arithmetic number, because the mean of its divisors is an integer number (333713389).

Almost surely, 2^667426777 is an apocalyptic number.

It is an amenable number.

667426777 is a deficient number, since it is larger than the sum of its proper divisors (1).

667426777 is an equidigital number, since it uses as much as digits as its factorization.

667426777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4148928, while the sum is 52.

The square root of 667426777 is about 25834.6042547588. The cubic root of 667426777 is about 873.9123474036.

The spelling of 667426777 in words is "six hundred sixty-seven million, four hundred twenty-six thousand, seven hundred seventy-seven".