643061 has 2 divisors, whose sum is σ = 643062. Its totient is φ = 643060.

The previous prime is 643051. The next prime is 643073. The reversal of 643061 is 160346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 600625 + 42436 = 775^2 + 206^2 .

It is a cyclic number.

It is not a de Polignac number, because 643061 - 2⁶ = 642997 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321530 + 321531.

It is an arithmetic number, because the mean of its divisors is an integer number (321531).

2⁶⁴³⁰⁶¹ is an apocalyptic number.

It is an amenable number.

643061 is a deficient number, since it is larger than the sum of its proper divisors (1).

643061 is an equidigital number, since it uses as much as digits as its factorization.

643061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 643061 is about 801.9108429246. The cubic root of 643061 is about 86.3145592400.

It can be divided in two parts, 64 and 3061, that added together give a 5-th power (3125 = 5⁵).

The spelling of 643061 in words is "six hundred forty-three thousand, sixty-one".