628421869 has 2 divisors, whose sum is σ = 628421870. Its totient is φ = 628421868.

The previous prime is 628421777. The next prime is 628421891. The reversal of 628421869 is 968124826.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 600985225 + 27436644 = 24515^2 + 5238^2 .

It is a cyclic number.

It is not a de Polignac number, because 628421869 - 2¹⁵ = 628389101 is a prime.

It is a super-2 number, since 2×628421869² = 789828090874906322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (628421069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 314210934 + 314210935.

It is an arithmetic number, because the mean of its divisors is an integer number (314210935).

Almost surely, 2^628421869 is an apocalyptic number.

It is an amenable number.

628421869 is a deficient number, since it is larger than the sum of its proper divisors (1).

628421869 is an equidigital number, since it uses as much as digits as its factorization.

628421869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 331776, while the sum is 46.

The square root of 628421869 is about 25068.3439620570. The cubic root of 628421869 is about 856.5454846494.

The spelling of 628421869 in words is "six hundred twenty-eight million, four hundred twenty-one thousand, eight hundred sixty-nine".