628561 has 2 divisors, whose sum is σ = 628562. Its totient is φ = 628560.

The previous prime is 628547. The next prime is 628583. The reversal of 628561 is 165826.

628561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 398161 + 230400 = 631^2 + 480^2 .

It is a cyclic number.

It is not a de Polignac number, because 628561 - 2⁹ = 628049 is a prime.

628561 is a lucky number.

It is a nialpdrome in base 16.

It is not a weakly prime, because it can be changed into another prime (628591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 314280 + 314281.

It is an arithmetic number, because the mean of its divisors is an integer number (314281).

2⁶²⁸⁵⁶¹ is an apocalyptic number.

It is an amenable number.

628561 is a deficient number, since it is larger than the sum of its proper divisors (1).

628561 is an equidigital number, since it uses as much as digits as its factorization.

628561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2880, while the sum is 28.

The square root of 628561 is about 792.8183903013. The cubic root of 628561 is about 85.6608692314.

Subtracting from 628561 its product of digits (2880), we obtain a square (625681 = 791²).

The spelling of 628561 in words is "six hundred twenty-eight thousand, five hundred sixty-one".