Search a number
777421 is a prime number

777421 has 2 divisors, whose sum is σ = 777422. Its totient is φ = 777420.

The previous prime is 777419. The next prime is 777431. The reversal of 777421 is 124777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 741321 + 36100 = 861^2 + 190^2 .

It is an emirp because it is prime and its reverse (124777) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 777421 - 21 = 777419 is a prime.

It is a super-2 number, since 2×7774212 = 1208766822482, which contains 22 as substring.

Together with 777419, it forms a pair of twin primes.

777421 is a lucky number.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 777421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (777431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 388710 + 388711.

It is an arithmetic number, because the mean of its divisors is an integer number (388711).

2777421 is an apocalyptic number.

It is an amenable number.

777421 is a deficient number, since it is larger than the sum of its proper divisors (1).

777421 is an equidigital number, since it uses as much as digits as its factorization.

777421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2744, while the sum is 28.

The square root of 777421 is about 881.7148064992. The cubic root of 777421 is about 91.9500753072.

The spelling of 777421 in words is "seven hundred seventy-seven thousand, four hundred twenty-one", and thus it is an iban number.