628243261 has 2 divisors, whose sum is σ = 628243262. Its totient is φ = 628243260.

The previous prime is 628243163. The next prime is 628243277. The reversal of 628243261 is 162342826.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 436559236 + 191684025 = 20894^2 + 13845^2 .

It is a cyclic number.

It is not a de Polignac number, because 628243261 - 2²¹ = 626146109 is a prime.

It is equal to p_32720596 and since 628243261 and 32720596 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (628243061) 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, 314121630 + 314121631.

It is an arithmetic number, because the mean of its divisors is an integer number (314121631).

Almost surely, 2^628243261 is an apocalyptic number.

It is an amenable number.

628243261 is a deficient number, since it is larger than the sum of its proper divisors (1).

628243261 is an equidigital number, since it uses as much as digits as its factorization.

628243261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27648, while the sum is 34.

The square root of 628243261 is about 25064.7812876953. The cubic root of 628243261 is about 856.4643287787.

The spelling of 628243261 in words is "six hundred twenty-eight million, two hundred forty-three thousand, two hundred sixty-one".