628087861 has 2 divisors, whose sum is σ = 628087862. Its totient is φ = 628087860.

The previous prime is 628087853. The next prime is 628087907. The reversal of 628087861 is 168780826.

It is an a-pointer prime, because the next prime (628087907) can be obtained adding 628087861 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 567154225 + 60933636 = 23815^2 + 7806^2 .

It is a cyclic number.

It is not a de Polignac number, because 628087861 - 2³ = 628087853 is a prime.

It is a super-3 number, since 3×628087861³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (628084861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 314043930 + 314043931.

It is an arithmetic number, because the mean of its divisors is an integer number (314043931).

Almost surely, 2^628087861 is an apocalyptic number.

It is an amenable number.

628087861 is a deficient number, since it is larger than the sum of its proper divisors (1).

628087861 is an equidigital number, since it uses as much as digits as its factorization.

628087861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 258048, while the sum is 46.

The square root of 628087861 is about 25061.6811287671. The cubic root of 628087861 is about 856.3937056404.

The spelling of 628087861 in words is "six hundred twenty-eight million, eighty-seven thousand, eight hundred sixty-one".