643242156205 has 8 divisors (see below), whose sum is σ = 842062459104. Its totient is φ = 467812477200.

The previous prime is 643242156083. The next prime is 643242156281. The reversal of 643242156205 is 502651242346.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 643242156205 - 2¹¹ = 643242154157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 5847655911 + ... + 5847656020.

It is an arithmetic number, because the mean of its divisors is an integer number (105257807388).

Almost surely, 2^643242156205 is an apocalyptic number.

It is an amenable number.

643242156205 is a deficient number, since it is larger than the sum of its proper divisors (198820302899).

643242156205 is a wasteful number, since it uses less digits than its factorization.

643242156205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11695311947.

The product of its (nonzero) digits is 345600, while the sum is 40.

The spelling of 643242156205 in words is "six hundred forty-three billion, two hundred forty-two million, one hundred fifty-six thousand, two hundred five".