628506521 has 4 divisors (see below), whose sum is σ = 629393700. Its totient is φ = 627619344.

The previous prime is 628506517. The next prime is 628506523. The reversal of 628506521 is 125605826.

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 276756496 + 351750025 = 16636^2 + 18755^2 .

It is a cyclic number.

It is not a de Polignac number, because 628506521 - 2² = 628506517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (628506523) 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, 442526 + ... + 443943.

It is an arithmetic number, because the mean of its divisors is an integer number (157348425).

Almost surely, 2^628506521 is an apocalyptic number.

It is an amenable number.

628506521 is a deficient number, since it is larger than the sum of its proper divisors (887179).

628506521 is an equidigital number, since it uses as much as digits as its factorization.

628506521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 887178.

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 628506521 is about 25070.0323294566. The cubic root of 628506521 is about 856.5839434388.

The spelling of 628506521 in words is "six hundred twenty-eight million, five hundred six thousand, five hundred twenty-one".