628881 has 32 divisors (see below), whose sum is σ = 1036800. Its totient is φ = 334080.

The previous prime is 628877. The next prime is 628909. The reversal of 628881 is 188826.

628881 is a nontrivial binomial coefficient, being equal to C(1122, 2).

It is not a de Polignac number, because 628881 - 2² = 628877 is a prime.

It is a super-2 number, since 2×628881² = 790982624322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

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 polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10630 + ... + 10688.

It is an arithmetic number, because the mean of its divisors is an integer number (32400).

2⁶²⁸⁸⁸¹ is an apocalyptic number.

628881 is the 1121-st triangular number and also the 561-st hexagonal number.

It is an amenable number.

628881 is a deficient number, since it is larger than the sum of its proper divisors (407919).

628881 is a wasteful number, since it uses less digits than its factorization.

628881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109.

The product of its digits is 6144, while the sum is 33.

The square root of 628881 is about 793.0201762881. The cubic root of 628881 is about 85.6754033963.

The spelling of 628881 in words is "six hundred twenty-eight thousand, eight hundred eighty-one".