643212426 has 16 divisors (see below), whose sum is σ = 1307514528. Its totient is φ = 210889200.

The previous prime is 643212389. The next prime is 643212433. The reversal of 643212426 is 624212346.

It is a super-3 number, since 3×643212426³ (a number of 27 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643212393 and 643212402.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 878340 + ... + 879071.

It is an arithmetic number, because the mean of its divisors is an integer number (81719658).

Almost surely, 2^643212426 is an apocalyptic number.

643212426 is an abundant number, since it is smaller than the sum of its proper divisors (664302102).

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

643212426 is a wasteful number, since it uses less digits than its factorization.

643212426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1757477.

The product of its digits is 13824, while the sum is 30.

The square root of 643212426 is about 25361.6329521583. The cubic root of 643212426 is about 863.2133373603.

The spelling of 643212426 in words is "six hundred forty-three million, two hundred twelve thousand, four hundred twenty-six".