643312734 has 16 divisors (see below), whose sum is σ = 1293736080. Its totient is φ = 213252480.

The previous prime is 643312687. The next prime is 643312739. The reversal of 643312734 is 437213346.

It is a junction number, because it is equal to n+sod(n) for n = 643312695 and 643312704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643312739) 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, 295099 + ... + 297270.

It is an arithmetic number, because the mean of its divisors is an integer number (80858505).

Almost surely, 2^643312734 is an apocalyptic number.

643312734 is an abundant number, since it is smaller than the sum of its proper divisors (650423346).

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

643312734 is a wasteful number, since it uses less digits than its factorization.

643312734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 592555.

The product of its digits is 36288, while the sum is 33.

The square root of 643312734 is about 25363.6104291168. The cubic root of 643312734 is about 863.2582072972.

The spelling of 643312734 in words is "six hundred forty-three million, three hundred twelve thousand, seven hundred thirty-four".