628987889 has 2 divisors, whose sum is σ = 628987890. Its totient is φ = 628987888.

The previous prime is 628987829. The next prime is 628987973. The reversal of 628987889 is 988789826.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 615883489 + 13104400 = 24817^2 + 3620^2 .

It is a cyclic number.

It is not a de Polignac number, because 628987889 - 2⁸ = 628987633 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (628987829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 314493944 + 314493945.

It is an arithmetic number, because the mean of its divisors is an integer number (314493945).

Almost surely, 2^628987889 is an apocalyptic number.

It is an amenable number.

628987889 is a deficient number, since it is larger than the sum of its proper divisors (1).

628987889 is an equidigital number, since it uses as much as digits as its factorization.

628987889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27869184, while the sum is 65.

The square root of 628987889 is about 25079.6309582099. The cubic root of 628987889 is about 856.8025711769.

The spelling of 628987889 in words is "six hundred twenty-eight million, nine hundred eighty-seven thousand, eight hundred eighty-nine".