643212106 has 4 divisors (see below), whose sum is σ = 964818162. Its totient is φ = 321606052.

The previous prime is 643212071. The next prime is 643212151. The reversal of 643212106 is 601212346.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 643078881 + 133225 = 25359^2 + 365^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160803025 + ... + 160803028.

Almost surely, 2^643212106 is an apocalyptic number.

643212106 is a deficient number, since it is larger than the sum of its proper divisors (321606056).

643212106 is a wasteful number, since it uses less digits than its factorization.

643212106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321606055.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 643212106 is about 25361.6266434154. The cubic root of 643212106 is about 863.2131942100.

The spelling of 643212106 in words is "six hundred forty-three million, two hundred twelve thousand, one hundred six".