643212205 has 8 divisors (see below), whose sum is σ = 772039800. Its totient is φ = 514446336.

The previous prime is 643212197. The next prime is 643212247. The reversal of 643212205 is 502212346.

It can be written as a sum of positive squares in 4 ways, for example, as 121044004 + 522168201 = 11002^2 + 22851^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 643212205 - 2³ = 643212197 is a prime.

It is a super-3 number, since 3×643212205³ (a number of 27 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 643212205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11901 + ... + 37789.

It is an arithmetic number, because the mean of its divisors is an integer number (96504975).

Almost surely, 2^643212205 is an apocalyptic number.

It is an amenable number.

643212205 is a deficient number, since it is larger than the sum of its proper divisors (128827595).

643212205 is a wasteful number, since it uses less digits than its factorization.

643212205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30863.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 643212205 is about 25361.6285951829. The cubic root of 643212205 is about 863.2132384971.

The spelling of 643212205 in words is "six hundred forty-three million, two hundred twelve thousand, two hundred five".