628134921 has 12 divisors (see below), whose sum is σ = 960677172. Its totient is φ = 394123776.

The previous prime is 628134919. The next prime is 628134967. The reversal of 628134921 is 129431826.

628134921 is a `hidden beast` number, since 628 + 1 + 3 + 4 + 9 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 518199696 + 109935225 = 22764^2 + 10485^2 .

It is not a de Polignac number, because 628134921 - 2¹ = 628134919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (628134901) 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 11 ways as a sum of consecutive naturals, for example, 2052576 + ... + 2052881.

It is an arithmetic number, because the mean of its divisors is an integer number (80056431).

Almost surely, 2^628134921 is an apocalyptic number.

It is an amenable number.

628134921 is a deficient number, since it is larger than the sum of its proper divisors (332542251).

628134921 is a wasteful number, since it uses less digits than its factorization.

628134921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4105480 (or 4105477 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 628134921 is about 25062.6199947252. The cubic root of 628134921 is about 856.4150937740.

The spelling of 628134921 in words is "six hundred twenty-eight million, one hundred thirty-four thousand, nine hundred twenty-one".