643032311 has 4 divisors (see below), whose sum is σ = 648931800. Its totient is φ = 637132824.

The previous prime is 643032307. The next prime is 643032329. The reversal of 643032311 is 113230346.

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

It is a cyclic number.

It is not a de Polignac number, because 643032311 - 2² = 643032307 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643032391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2949581 + ... + 2949798.

It is an arithmetic number, because the mean of its divisors is an integer number (162232950).

Almost surely, 2^643032311 is an apocalyptic number.

643032311 is a deficient number, since it is larger than the sum of its proper divisors (5899489).

643032311 is a wasteful number, since it uses less digits than its factorization.

643032311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5899488.

The product of its (nonzero) digits is 1296, while the sum is 23.

The square root of 643032311 is about 25358.0817689351. The cubic root of 643032311 is about 863.1327563171.

Adding to 643032311 its reverse (113230346), we get a palindrome (756262657).

The spelling of 643032311 in words is "six hundred forty-three million, thirty-two thousand, three hundred eleven".