643337380501001 has 2 divisors, whose sum is σ = 643337380501002. Its totient is φ = 643337380501000.

The previous prime is 643337380500929. The next prime is 643337380501003. The reversal of 643337380501001 is 100105083733346.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 579675492755401 + 63661887745600 = 24076451^2 + 7978840^2 .

It is a cyclic number.

It is not a de Polignac number, because 643337380501001 - 2³⁴ = 643320200631817 is a prime.

Together with 643337380501003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643337380501003) 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 as a sum of consecutive naturals, namely, 321668690250500 + 321668690250501.

It is an arithmetic number, because the mean of its divisors is an integer number (321668690250501).

Almost surely, 2^{643337380501001} is an apocalyptic number.

It is an amenable number.

643337380501001 is a deficient number, since it is larger than the sum of its proper divisors (1).

643337380501001 is an equidigital number, since it uses as much as digits as its factorization.

643337380501001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 544320, while the sum is 44.

The spelling of 643337380501001 in words is "six hundred forty-three trillion, three hundred thirty-seven billion, three hundred eighty million, five hundred one thousand, one".