628381 has 4 divisors (see below), whose sum is σ = 676732. Its totient is φ = 580032.

The previous prime is 628379. The next prime is 628391. The reversal of 628381 is 183826.

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

It can be written as a sum of positive squares in 2 ways, for example, as 320356 + 308025 = 566^2 + 555^2 .

It is a cyclic number.

It is not a de Polignac number, because 628381 - 2¹ = 628379 is a prime.

It is a super-2 number, since 2×628381² = 789725362322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628301) 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, 24156 + ... + 24181.

It is an arithmetic number, because the mean of its divisors is an integer number (169183).

2⁶²⁸³⁸¹ is an apocalyptic number.

It is an amenable number.

628381 is a deficient number, since it is larger than the sum of its proper divisors (48351).

628381 is a wasteful number, since it uses less digits than its factorization.

628381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48350.

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

The square root of 628381 is about 792.7048631111. The cubic root of 628381 is about 85.6526915957.

The spelling of 628381 in words is "six hundred twenty-eight thousand, three hundred eighty-one".