628630391 has 4 divisors (see below), whose sum is σ = 633219072. Its totient is φ = 624041712.

The previous prime is 628630283. The next prime is 628630393. The reversal of 628630391 is 193036826.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 193036826 = 2 ⋅96518413.

It is a cyclic number.

It is not a de Polignac number, because 628630391 - 2¹⁰ = 628629367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628630393) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2294135 + ... + 2294408.

It is an arithmetic number, because the mean of its divisors is an integer number (158304768).

Almost surely, 2^628630391 is an apocalyptic number.

628630391 is a deficient number, since it is larger than the sum of its proper divisors (4588681).

628630391 is a wasteful number, since it uses less digits than its factorization.

628630391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4588680.

The product of its (nonzero) digits is 46656, while the sum is 38.

The square root of 628630391 is about 25072.5026872070. The cubic root of 628630391 is about 856.6402133844.

The spelling of 628630391 in words is "six hundred twenty-eight million, six hundred thirty thousand, three hundred ninety-one".