643354741 has 4 divisors (see below), whose sum is σ = 643843084. Its totient is φ = 642866400.

The previous prime is 643354721. The next prime is 643354771. The reversal of 643354741 is 147453346.

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

It can be written as a sum of positive squares in 2 ways, for example, as 410670225 + 232684516 = 20265^2 + 15254^2 .

It is a cyclic number.

It is not a de Polignac number, because 643354741 - 2²⁹ = 106483829 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 643354741.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643354711) 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, 242190 + ... + 244831.

It is an arithmetic number, because the mean of its divisors is an integer number (160960771).

Almost surely, 2^643354741 is an apocalyptic number.

It is an amenable number.

643354741 is a deficient number, since it is larger than the sum of its proper divisors (488343).

643354741 is a wasteful number, since it uses less digits than its factorization.

643354741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488342.

The product of its digits is 120960, while the sum is 37.

The square root of 643354741 is about 25364.4385114278. The cubic root of 643354741 is about 863.2769965507.

The spelling of 643354741 in words is "six hundred forty-three million, three hundred fifty-four thousand, seven hundred forty-one".