628831 has 4 divisors (see below), whose sum is σ = 718672. Its totient is φ = 538992.

The previous prime is 628819. The next prime is 628841. The reversal of 628831 is 138826.

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 628831 - 2⁵ = 628799 is a prime.

It is a super-2 number, since 2×628831² = 790856853122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 628831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44910 + ... + 44923.

It is an arithmetic number, because the mean of its divisors is an integer number (179668).

2⁶²⁸⁸³¹ is an apocalyptic number.

628831 is a deficient number, since it is larger than the sum of its proper divisors (89841).

628831 is an equidigital number, since it uses as much as digits as its factorization.

628831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89840.

The product of its digits is 2304, while the sum is 28.

The square root of 628831 is about 792.9886506124. The cubic root of 628831 is about 85.6731327581.

The spelling of 628831 in words is "six hundred twenty-eight thousand, eight hundred thirty-one".