628891 has 4 divisors (see below), whose sum is σ = 636552. Its totient is φ = 621232.

The previous prime is 628877. The next prime is 628909. The reversal of 628891 is 198826.

628891 is nontrivially palindromic in base 5.

628891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 628891 - 2⁹ = 628379 is a prime.

It is a Duffinian number.

628891 is a lucky number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (628801) 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, 3706 + ... + 3871.

It is an arithmetic number, because the mean of its divisors is an integer number (159138).

2⁶²⁸⁸⁹¹ is an apocalyptic number.

628891 is a deficient number, since it is larger than the sum of its proper divisors (7661).

628891 is an equidigital number, since it uses as much as digits as its factorization.

628891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7660.

The product of its digits is 6912, while the sum is 34.

The square root of 628891 is about 793.0264812729. The cubic root of 628891 is about 85.6758575095.

The spelling of 628891 in words is "six hundred twenty-eight thousand, eight hundred ninety-one".