643213442 has 4 divisors (see below), whose sum is σ = 964820166. Its totient is φ = 321606720.

The previous prime is 643213421. The next prime is 643213507. The reversal of 643213442 is 244312346.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 244312346 = 2 ⋅122156173.

It can be written as a sum of positive squares in only one way, i.e., 583753921 + 59459521 = 24161^2 + 7711^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160803359 + ... + 160803362.

Almost surely, 2^643213442 is an apocalyptic number.

643213442 is a deficient number, since it is larger than the sum of its proper divisors (321606724).

643213442 is a wasteful number, since it uses less digits than its factorization.

643213442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321606723.

The product of its digits is 13824, while the sum is 29.

The square root of 643213442 is about 25361.6529824063. The cubic root of 643213442 is about 863.2137918625.

Adding to 643213442 its reverse (244312346), we get a palindrome (887525788).

The spelling of 643213442 in words is "six hundred forty-three million, two hundred thirteen thousand, four hundred forty-two".