643161587 has 2 divisors, whose sum is σ = 643161588. Its totient is φ = 643161586.

The previous prime is 643161569. The next prime is 643161643. The reversal of 643161587 is 785161346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643161587 - 2¹⁴ = 643145203 is a prime.

It is a super-3 number, since 3×643161587³ (a number of 27 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (643161487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321580793 + 321580794.

It is an arithmetic number, because the mean of its divisors is an integer number (321580794).

Almost surely, 2^643161587 is an apocalyptic number.

643161587 is a deficient number, since it is larger than the sum of its proper divisors (1).

643161587 is an equidigital number, since it uses as much as digits as its factorization.

643161587 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 41.

The square root of 643161587 is about 25360.6306506759. The cubic root of 643161587 is about 863.1905941953.

The spelling of 643161587 in words is "six hundred forty-three million, one hundred sixty-one thousand, five hundred eighty-seven".