643784541 has 8 divisors (see below), whose sum is σ = 858846624. Its totient is φ = 428956080.

The previous prime is 643784527. The next prime is 643784567. The reversal of 643784541 is 145487346.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 643784541 - 2¹¹ = 643782493 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643784493 and 643784502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643714541) 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, 51870 + ... + 63071.

It is an arithmetic number, because the mean of its divisors is an integer number (107355828).

Almost surely, 2^643784541 is an apocalyptic number.

It is an amenable number.

643784541 is a deficient number, since it is larger than the sum of its proper divisors (215062083).

643784541 is a wasteful number, since it uses less digits than its factorization.

643784541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116811.

The product of its digits is 322560, while the sum is 42.

The square root of 643784541 is about 25372.9095887720. The cubic root of 643784541 is about 863.4691942271.

The spelling of 643784541 in words is "six hundred forty-three million, seven hundred eighty-four thousand, five hundred forty-one".