628321521 has 32 divisors (see below), whose sum is σ = 897085440. Its totient is φ = 390259584.

The previous prime is 628321517. The next prime is 628321543. The reversal of 628321521 is 125123826.

It is not a de Polignac number, because 628321521 - 2² = 628321517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (628321571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1014750 + ... + 1015368.

It is an arithmetic number, because the mean of its divisors is an integer number (28033920).

Almost surely, 2^628321521 is an apocalyptic number.

It is an amenable number.

628321521 is a deficient number, since it is larger than the sum of its proper divisors (268763919).

628321521 is a wasteful number, since it uses less digits than its factorization.

628321521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1005.

The product of its digits is 5760, while the sum is 30.

The square root of 628321521 is about 25066.3423937359. The cubic root of 628321521 is about 856.4998904364.

The spelling of 628321521 in words is "six hundred twenty-eight million, three hundred twenty-one thousand, five hundred twenty-one".