627778561 has 2 divisors, whose sum is σ = 627778562. Its totient is φ = 627778560.

The previous prime is 627778553. The next prime is 627778589. The reversal of 627778561 is 165877726.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 407434225 + 220344336 = 20185^2 + 14844^2 .

It is a cyclic number.

It is not a de Polignac number, because 627778561 - 2³ = 627778553 is a prime.

It is not a weakly prime, because it can be changed into another prime (627778531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 313889280 + 313889281.

It is an arithmetic number, because the mean of its divisors is an integer number (313889281).

Almost surely, 2^627778561 is an apocalyptic number.

It is an amenable number.

627778561 is a deficient number, since it is larger than the sum of its proper divisors (1).

627778561 is an equidigital number, since it uses as much as digits as its factorization.

627778561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 987840, while the sum is 49.

The square root of 627778561 is about 25055.5095937001. The cubic root of 627778561 is about 856.2531063805.

The spelling of 627778561 in words is "six hundred twenty-seven million, seven hundred seventy-eight thousand, five hundred sixty-one".