628219661 has 2 divisors, whose sum is σ = 628219662. Its totient is φ = 628219660.

The previous prime is 628219607. The next prime is 628219673. The reversal of 628219661 is 166912826.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 349129225 + 279090436 = 18685^2 + 16706^2 .

It is a cyclic number.

It is not a de Polignac number, because 628219661 - 2²² = 624025357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (628219961) 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, 314109830 + 314109831.

It is an arithmetic number, because the mean of its divisors is an integer number (314109831).

Almost surely, 2^628219661 is an apocalyptic number.

It is an amenable number.

628219661 is a deficient number, since it is larger than the sum of its proper divisors (1).

628219661 is an equidigital number, since it uses as much as digits as its factorization.

628219661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 41.

The square root of 628219661 is about 25064.3105031836. The cubic root of 628219661 is about 856.4536042645.

The spelling of 628219661 in words is "six hundred twenty-eight million, two hundred nineteen thousand, six hundred sixty-one".