643224215265666 has 64 divisors (see below), whose sum is σ = 1414284186470400. Its totient is φ = 194119889648256.

The previous prime is 643224215265661. The next prime is 643224215265703. The reversal of 643224215265666 is 666562512422346.

It is a super-2 number, since 2×643224215265666² (a number of 30 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (643224215265661) 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 in 31 ways as a sum of consecutive naturals, for example, 105683766 + ... + 111604241.

It is an arithmetic number, because the mean of its divisors is an integer number (22098190413600).

Almost surely, 2^{643224215265666} is an apocalyptic number.

643224215265666 is an abundant number, since it is smaller than the sum of its proper divisors (771059971204734).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643224215265666 is a wasteful number, since it uses less digits than its factorization.

643224215265666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217289183.

The product of its digits is 149299200, while the sum is 60.

The spelling of 643224215265666 in words is "six hundred forty-three trillion, two hundred twenty-four billion, two hundred fifteen million, two hundred sixty-five thousand, six hundred sixty-six".