628631 has 4 divisors (see below), whose sum is σ = 633000. Its totient is φ = 624264.

The previous prime is 628591. The next prime is 628651. The reversal of 628631 is 136826.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-628631 is a prime.

It is a super-2 number, since 2×628631² = 790353868322, 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 628631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628651) 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, 1961 + ... + 2258.

It is an arithmetic number, because the mean of its divisors is an integer number (158250).

2⁶²⁸⁶³¹ is an apocalyptic number.

628631 is a deficient number, since it is larger than the sum of its proper divisors (4369).

628631 is a wasteful number, since it uses less digits than its factorization.

628631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4368.

The product of its digits is 1728, while the sum is 26.

The square root of 628631 is about 792.8625353742. The cubic root of 628631 is about 85.6640490014.

The spelling of 628631 in words is "six hundred twenty-eight thousand, six hundred thirty-one".