775978477 has 2 divisors, whose sum is σ = 775978478. Its totient is φ = 775978476.

The previous prime is 775978471. The next prime is 775978493. The reversal of 775978477 is 774879577.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 728244196 + 47734281 = 26986^2 + 6909^2 .

It is an emirp because it is prime and its reverse (774879577) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-775978477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (775978471) 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, 387989238 + 387989239.

It is an arithmetic number, because the mean of its divisors is an integer number (387989239).

Almost surely, 2^775978477 is an apocalyptic number.

It is an amenable number.

775978477 is a deficient number, since it is larger than the sum of its proper divisors (1).

775978477 is an equidigital number, since it uses as much as digits as its factorization.

775978477 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24202080, while the sum is 61.

The square root of 775978477 is about 27856.3902363533. The cubic root of 775978477 is about 918.9316825083.

The spelling of 775978477 in words is "seven hundred seventy-five million, nine hundred seventy-eight thousand, four hundred seventy-seven".