643612834 has 16 divisors (see below), whose sum is σ = 1023072120. Its totient is φ = 303130240.

The previous prime is 643612831. The next prime is 643612847. The reversal of 643612834 is 438216346.

It can be written as a sum of positive squares in 4 ways, for example, as 554367025 + 89245809 = 23545^2 + 9447^2 .

It is a junction number, because it is equal to n+sod(n) for n = 643612793 and 643612802.

It is not an unprimeable number, because it can be changed into a prime (643612831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132949 + ... + 137704.

Almost surely, 2^643612834 is an apocalyptic number.

643612834 is a deficient number, since it is larger than the sum of its proper divisors (379459286).

643612834 is a wasteful number, since it uses less digits than its factorization.

643612834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270725.

The product of its digits is 82944, while the sum is 37.

The square root of 643612834 is about 25369.5256952116. The cubic root of 643612834 is about 863.3924206697.

It can be divided in two parts, 643612 and 834, that added together give a palindrome (644446).

The spelling of 643612834 in words is "six hundred forty-three million, six hundred twelve thousand, eight hundred thirty-four".